Biology subjects

Cascalho, M.

Publications and source records attributed to Cascalho, M..

5 recordsLinked to original sources

bioRxiv2025

Restoration of ovarian endocrine function with encapsulated immune isolated human ovarian xenograft in ovariectomized mice

Anti-cancer treatments cause premature depletion of the non-renewable ovarian reserve of follicles, the source of key steroid hormones, leading to premature ovarian insufficiency (POI) in 50% of pediatric cancer survivors. Patients with POI, especially at the onset of pubertal development, experience significant endocrine complications, including delayed growth, elevated risks of obesity and diabetes, and accelerated cardiovascular, musculoskeletal and neurological disorders as adults. The only approved pharmacological treatment for POI is an off-label prescribed hormone replacement therapy, which does not replace physiologically functioning ovaries. To restore production of ovarian hormones and protect against immune-mediated injury, we developed a hydrogel-based capsule for implantation of donor ovarian tissue. We evaluated the restoration of ovarian endocrine function in ovariectomized immunodeficient (NOD scid gamma, NSG) mice implanted with encapsulated xenografts over 20 weeks through daily vaginal cytology, hormone measurements and histological analysis of explanted human xenografts. The encapsulated xenografts integrated into the murine hypothalamus-pituitary-gonad (HPG) axis responding to circulating murine gonadotropins and restoring ovarian endocrine function. As controls, we implanted non encapsulated human ovarian xenografts comparable in size. Without the need for exogeneous stimulation, the estrous cyclicity resumed in both groups of mice 12 weeks post implantation and all mice regularly cycled experiencing between 3 to 8 estrous cycles in 20 weeks. The levels of estradiol gradually increased reaching on average 50pg/mL 20 weeks post implantation. Morphological analysis of the encapsulated grafts revealed presence of large antral follicles, [~]3mm in diameter, consistent with regular cyclicity and measurable levels of circulating hormones. This work demonstrates that endocrine function of encapsulated human ovarian tissue was not affected by the encapsulation and integrated with the host physiology similarly to the non-encapsulated controls.

bioengineering↗

bioRxiv2024

Complement C3d enables protective immunity capable of distinguishing spontaneously transformed from non-transformed cells

Immune-surveillance depends in part on the recognition of peptide variants by T cell antigen receptors. Given that both normal B cells and malignant B cells accumulate mutations we chose a murine model of multiple myeloma to test conditions to induce cell-mediated immunity targeting malignant plasma cell (PC) clones but sparing of normal PCs. Revealing a novel function for intracellular C3d, we discovered that C3d engaged T cell responses against malignant plasma cells in the bone marrow of mice that had developed multiple myeloma spontaneously. Our results show that C3d internalized by cells augments immune surveillance by several mechanisms. In one, C3d induces a master transcription regulator, E2f1, to increase the expression of long non-coding (lnc) RNAs, to generate peptides for MHC-I presentation and increase MHC-I expression. In another, C3d increases expression of RNAs encoding ribosomal proteins linked to processing of defective ribosomal products (DRiPs) that arise from non-canonical translation and known to promote immunosurveillance. Cancer cells are uniquely susceptible to increased expression and presentation of mutant peptides given the extent of protein misfolding and accumulation of somatic mutations. Accordingly, although C3d can be internalized by any cell, C3d preferentially targets malignant clones by evoking specific T cell mediated immunity (CMI) and sparing most non-transformed polyclonal B cells and plasma cells with lower mutation loads. Malignant plasma cell deletion was blocked by cyclosporin or by CD8 depletion confirming that endogenous T cells mediated malignant clone clearance. Besides the potential for therapeutic application our results highlight how intracellular C3d modifies cellular metabolism to augment immune surveillance. One Sentence SummaryWe show that intracellular soluble fragment 3d of complement (C3d) induces regression of spontaneous multiple myeloma in mice reducing tumor burden by 10 fold, after 8 weeks. C3d enables cell-mediated immunity to target multiple myeloma clones sparing non-transformed polyclonal B cells and plasma cells with lower mutation loads. We show that C3d increases the expression of ribosomal subunits associated with the translation of defective ribosomal products (DRiPs). C3d also decreases expression of protein arginine methyl transferase (PRMT) 5 which in turn relieves E2f1 repression increasing the expression of Lnc RNAs and derived peptides that evoke anti-tumor cellular immunity. The approach increases MHC-I expression by tumor cells and generates a CMI response that overcomes tumor immune-evasion strategies. SignificanceTumors are immunogenic in part because of somatic mutations that originate novel peptides that once presented on MHC engage cell-mediated immunity (CMI). However, in spite of the higher mutation load most tumors evade immunity. We discovered that a component of the complement system (C3d) overcomes tumor immune evasion by augmenting expression of ribosomal proteins and lncRNAs linked to the presentation of novel peptides by tumor cells. C3d induced CMI targets cancer cells sparing non transformed cells uncovering a novel function for complement in immune surveillance.

immunology↗

bioRxiv2021

Encapsulated allografts preclude host sensitization and promote ovarian endocrine function in ovariectomized young rhesus monkeys and sensitized mice

Transplantation of allogeneic donor ovarian tissue holds great potential for female cancer survivors who often experience premature ovarian insufficiency. To avoid complications associated with immune suppression and to protect transplanted ovarian allografts from immune-mediated injury, we have developed an immuno-isolating hydrogel-based capsule that supports the function of ovarian allografts without triggering an immune response. Encapsulated ovarian allografts implanted in naive ovariectomized BALB/c mice responded to the circulating gonadotropins without direct revascularization and maintained function for 4 months, as evident by regular estrous cycles and presence of antral follicles in the retrieved grafts. Repeated implantations of encapsulated mouse ovarian allografts did not sensitize naive BALB/c mice in contrast to non-encapsulated controls, which was confirmed with undetectable levels of allo-antibody. Further, encapsulated allografts implanted in hosts previously sensitized by implantation of non-encapsulated allografts restored estrous cycles similarly to our results in naive recipients. Next, we tested the translational potential and efficiency of the immune-isolating capsule in a rhesus monkey model by implanting encapsulated ovarian auto- and allografts in young ovariectomized animals. The encapsulated ovarian grafts survived and restored basal levels of urinary estrone conjugate and pregnanediol 3-glucuronide during the approximate 4-5 month observation period. We demonstrate, for the first time, that encapsulation of ovarian allografts prevents sensitization and protects the allograft from rejection in young rhesus monkeys and in sensitized mice.

bioengineering↗

bioRxiv2021

A Combination Adjuvant for the Induction of Potent Antiviral Immune Responses for a Recombinant SARS-CoV-2 Protein Vaccine

Several SARS-CoV-2 vaccines have received EUAs, but many issues remain unresolved, including duration of conferred immunity and breadth of cross-protection. Adjuvants that enhance and shape adaptive immune responses that confer broad protection against SARS-CoV-2 variants will be pivotal for long-term protection. We developed an intranasal, rationally designed adjuvant integrating a nanoemulsion (NE) that activates TLRs and NLRP3 with an RNA agonist of RIG-I (IVT DI). The combination adjuvant with spike protein antigen elicited robust responses to SARS-CoV-2 in mice, with markedly enhanced TH1-biased cellular responses and high virus-neutralizing antibody titers towards both homologous SARS-CoV-2 and a variant harboring the N501Y mutation shared by B1.1.7, B.1.351 and P.1 variants. Furthermore, passive transfer of vaccination-induced antibodies protected naive mice against heterologous viral challenge. NE/IVT DI enables mucosal vaccination, and has the potential to improve the immune profile of a variety of SARS-CoV-2 vaccine candidates to provide effective cross-protection against future drift variants.

immunology↗

bioRxiv2021

Natural IgA and TNFRSF13B polymorphism: a double edged sword fueling balancing selection

TNFRSF13B encodes the "transmembrane-activator and CAML-interactor" (TACI) receptor, which drives plasma cell differentiation. Although TNFRSF13B supports host defense, dominant-negative TNFRSF13B alleles are common in humans and other species and only rarely associate with disease. We reasoned the high frequency of disruptive TNFRSF13B alleles reflects balancing selection, the loss of function conferring advantage in some settings. Testing that concept, we asked whether and how a common human dominant negative variant, TNFRSF13B A181E, imparts resistance to enteric pathogens. Mice engineered to express mono-allelic or bi-allelic A144E variants of tnrsf13B, corresponding to A181E exhibited striking resistance to pathogenicity and transmission of C. rodentium, a murine pathogen that models enterohemorrhagic E. coli, and resistance was principally owed to deficiency of natural IgA in the intestine. In wild type mice with gut IgA and in mutant mice fed IgA, binding of Ig induces expression of LEE encoded virulence genes, which confer pathogenicity and transmission. C. rodentium and probably some other enteric organisms thus appropriated binding of otherwise protective antibodies to signal induction of the virulence program and the high prevalence of TNFRSF13B dominant negative variants thus reflects balancing selection.

immunology↗