SERPINB3 Delays Glomerulonephritis and Attenuates the Lupus-Like Disease in Lupus Murine Models by Inducing a More Tolerogenic Immune Phenotype

SerpinB3: A Multifaceted Player in Health and Disease-Review and Future Perspectives

SerpinB3, a member of the serine-protease inhibitor family, has emerged as a crucial player in various physiological and pathological processes. Initially identified as an oncogenic factor in squamous cell carcinomas, SerpinB3's intricate involvement extends from fibrosis progression and cancer to cell protection in acute oxidative stress conditions. This review explores the multifaceted roles of SerpinB3, focusing on its implications in fibrosis, metabolic syndrome, carcinogenesis and immune system impairment. Furthermore, its involvement in tissue protection from oxidative stress and wound healing underscores its potential as diagnostic and therapeutic tool. Recent studies have described the therapeutic potential of targeting SerpinB3 through its upstream regulators, offering novel strategies for cancer treatment development. Overall, this review underscores the importance of further research to fully elucidate the mechanisms of action of SerpinB3 and to exploit its therapeutic potential across various medical conditions.

The pentraxin family in autoimmune disease

The pentraxins represent a family of multifunctional proteins composed of long and short pentamers. The latter includes serum amyloid P component (SAP) and C-reactive protein (CRP) whereas the former includes neuronal PTX1 and PTX2 (NPTX1 and NPTX2, respectively), PTX3 and PTX4. These serve as a bridge between adaptive immunity and innate immunity and a link between inflammation and immunity. Similarities and differences between long and short pentamers are examined and their roles in autoimmune disease are discussed. Increased CRP and PTX3 could indicate the activity of rheumatoid arthritis, systemic lupus erythematosus or other autoimmune diseases. Mechanistically, CRP and PTX3 may predict target organ injury, regulate bone metabolic immunity and maintain homeostasis as well as participate in vascular endothelial remodeling. Interestingly, PTX3 is pleiotropic, being involved in inflammation and tissue repair. Given the therapeutic potential of PTX3 and CRP, targeting these factors to exert a beneficial effect is the focus of research efforts. Unfortunately, studies on NPTX1, NPTX2, PTX4 and SAP are scarce and more research is clearly needed to elaborate their potential roles in autoimmune disease.

Novel Molecular Targets for Immune Surveillance of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common and aggressive cancer with a high mortality rate. The incidence of HCC is increasing worldwide, and the lack of effective screening programs often results in delayed diagnosis, making it a challenging disease to manage. Immunotherapy has emerged as a promising treatment option for different kinds of cancers, with the potential to stimulate the immune system to target cancer cells. However, the current immunotherapeutic approaches for HCC have shown limited efficacy. Since HCC arises within a complex tumour microenvironment (TME) characterized by the presence of various immune and stromal cell types, the understanding of this interaction is crucial for the identification of effective therapy. In this review, we highlight recent advances in our understanding of the TME of HCC and the immune cells involved in anti-tumour responses, including the identification of new possible targets for immunotherapy. We illustrate a possible classification of HCC based on the tumour immune infiltration and give evidence about the role of SerpinB3, a serine protease inhibitor involved in the regulation of the immune response in different cancers.

SERPINB3, Adult-Onset Immunodeficiency, and Generalized Pustular Psoriasis

BACKGROUND

Generalized pustular psoriasis (GPP; MIM 614204) is a rare and severe pustular autoinflammatory skin disease in which acute generalized erythema and scaling develop with numerous sterile pustules. GPP shares skin manifestations, especially pustular skin reaction, with adult-onset immunodeficiency (AOID) with anti-interferon-γ autoantibodies, an autoimmune disease.

METHODS

Clinical examinations and whole-exome sequencing (WES) were performed on 32 patients with pustular psoriasis phenotypes and 21 patients with AOID with pustular skin reaction. Immunohistochemical and histopathological studies were performed.

RESULTS

WES identified three Thai patients presenting with similar pustular phenotypes-two with a diagnosis of AOID and the other with GPP. A heterozygous missense variant chr18:g.61325778C>A NM_006919.2: c.438G>T; NP_008850.1: p.Lys146Asn; rs193238900 in SERPINB3 was identified in two patients: one with GPP and the other with AOID. The other patient who had AOID carried a heterozygous missense variant chr18:g.61323147T>C NM_006919.2: c.917A>G; NP_008850.1: p.Asp306Gly in SERPINB3. Immunohistochemical studies showed overexpression of SERPINA1 and SERPINB3, a hallmark of psoriatic skin lesions.

CONCLUSIONS

Genetic variants in SERPINB3 are associated with GPP and AOID with pustular skin reaction. The skin of patients with GPP and AOID carrying SERPINB3 mutations showed overexpression of SERPINB3 and SERPINA1. Clinically and genetically, GPP and AOID appear to share pathogenetic mechanisms.

Urinary serpin-A3 is an early predictor of clinical response to therapy in patients with proliferative lupus nephritis

We have previously reported that urinary excretion of serpin-A3 (uSerpA3) is significantly elevated in patients with active lupus nephritis (LN). Here, we evaluated the course of uSerpA3 during the first year of treatment and its association with response to therapy in patients with proliferative LN. The observational longitudinal study included 60 Mexican adults with proliferative LN followed during the first year after LN flare. uSerpA3 was detected by Western blot analysis at flare and after 3, 6, and 12 mo. The response to therapy was determined 1 yr after the LN flare. We evaluated the correlation between uSerpA3 and histological parameters at LN flare. The temporal association between uSerpA3 and response to therapy was analyzed with linear mixed models. uSerpA3 prognostic performance for response was evaluated with receiver-operating characteristic curves. Among the 60 patients studied, 21 patients (35%) were class III and 39 patients (65%) were class IV. uSerpA3 was higher in class IV than in class III LN (6.98 vs. 2.89 dots per in./mg creatinine, P = 0.01). Furthermore, uSerpA3 correlated with the histological activity index (r = 0.29, P = 0.02). There was a significant association between the temporal course of uSerpA3 and response to therapy. Responders showed a significant drop in uSerpA3 at 6 mo compared with LN flare (P < 0.001), whereas nonresponders persisted with elevated uSerpA3. Moreover, uSerpA3 was significantly lower at flare in responders compared with nonresponders (2.69 vs. 6.98 dots per in./mg creatinine, P < 0.05). Furthermore, uSerpA3 was able to identify nonresponders since 3 mo after LN flare (area under the curve: 0.77). In conclusion, uSerpA3 is an early indicator of kidney inflammation and predictor of the clinical response to therapy in patients with proliferative LN.NEW & NOTEWORTHY LN requires aggressive immunosuppression to improve long-term outcomes. Current indicators of remission take several months to normalize, prolonging treatment regiments in some cases. Serpin-A3 is present in urine of patients with proliferative LN. We evaluated the excretion of serpin-A3 in serial samples of patients with proliferative LN during the first year after flare. We found that uSerpA3 correlates with kidney inflammation and its decline at early points predicts the response to therapy 1 yr after flare.

FOXP3+ regulatory T cells and age-related diseases

Regulatory T (Treg) cells are critical for the maintenance of immune homeostasis. Dysregulation of Treg cells has been implicated in the pathogenesis of autoimmunity and chronic inflammation, while aging is characterized by an accumulation of inflammatory markers in the peripheral blood, a phenomenon known as 'inflammaging'. The relationship between Treg cells and age-related diseases remains to be further studied. Increasing evidence revealed that Treg cells' dysfunction occurs in aged patients, suggesting that immune therapies targeting Treg cells may be a promising approach to treat diseases such as cancers and autoimmune diseases. Furthermore, drugs targeting Treg cells show encouraging results and contribute to CD8⁺ T-cell-mediated cytotoxic killing of tumor and infected cells. In general, a better understanding of Treg cell function may help us to develop new immune therapies against aging. In this review, we discuss potential therapeutic strategies to modify immune responses of relevance for aging to prevent and treat age-related diseases, as well as the challenges posed by the translation of novel immune therapies into clinical practice.

Harnessing proteases for T regulatory cell immunotherapy

The immune system is tightly regulated by a subset of T cells defined as regulatory T cells (Tregs). Tregs maintain immune homeostasis by restraining unwarranted immune cell activation and effector function. Here, we discuss an important but underappreciated role of proteases in controlling Treg function. Proteases regulate a number of vital processes that determine T cell immune responses and some of them such as furin, ADAM (through regulating LAG receptor), MALT, and asparaginyl endopeptidase are implicated in Treg immunobiology. Targeted protease inhibition, using either small molecule inhibitors or gene deficient mice has demonstrated their specificity in modulating Treg function in experimental murine models. These data further highlight the ability of proteases to specifically regulate Tregs but no other T effector lineages. Taken together, it is apparent that incorporating proteases as targets within Treg cell engineering protocols may enable generation of robust Treg cellular therapeutics. These engineered Tregs may possess enhanced regulatory function along with resistance to lineage deviation in inflammatory disease such as colitis and graft versus host disease. Within this review, we summarize research on the role of proteases in regulating Treg function and discuss the translational potential of harnessing Treg function by targeting protease driven regulatory pathways.

Immunization with Pentraxin3 prevents transition from subclinical to clinical lupus nephritis in lupus-prone mice: Insights from renal ultrastructural findings

BACKGROUND

Pentraxin3 (PTX3) is an emerging player in lupus nephritis (LN). Anti-PTX3 antibodies showed to delay LN occurrence in vivo.

AIM

To evaluate renal changes following immunization with PTX3 in a murine model of LN.

MATERIALS AND METHODS

Twenty-two lupus-prone New Zealand Black/White (NZB/W)F1 mice were divided into two groups (n = 11) and subcutaneously injected with human recombinant (hr)PTX3 100 μg or phosphate buffer saline (PBS) 200 μl, three times 3 weeks apart, starting before development of proteinuria. Five mice from each group were scheduled for sacrifice at week 22 and 6 from each group at week 29. Renal lesions included electron-dense deposits (EDD), glomerular deposition of IgG, complement and PTX3 as markers of renal inflammation. They were evaluated by immunofluorescence (IF), confocal and immunoelectron microscopy (IEM). Validated semiquantitative scores were used when available to score renal lesions. Chi-squared test with Fisher exact test was used for comparison.

RESULTS

Nineteen out of 22 mice were sacrificed as scheduled. Only hrPTX3-immunized mice developed anti-PTX3 antibodies. Compared to PBS-injected mice, they displayed a dramatic decrease in glomerular deposits of IgG, C1q and PTX3, as well as in the amount of EDD (p = 0.006) and podocyte effacement (p = 0.043). Importantly, PTX3 was pinpointed inside the EDD and co-localized with nuclear material.

CONCLUSIONS

Immunization with PTX3 prevented progression from the preclinical to the clinical stage of LN, inciting anti-PTX3 antibodies and preventing renal PTX3 deposition. PTX3 is a novel component of EDD, submitting it as one initiating autoantigen in LN and as potential target for early treatment.