Respiratory mucosal delivery of next-generation COVID-19 vaccine provides robust protection against both ancestral and variant strains of SARS-CoV-2.

The emerging SARS-CoV-2 variants of concern (VOCs) threaten the effectiveness of current COVID-19 vaccines administered intramuscularly and designed to only target the spike protein. There is a pressing need to develop next-generation vaccine strategies for broader and long-lasting protection. Using adenoviral vectors (Ad) of human and chimpanzee origin, we evaluated Ad-vectored trivalent COVID-19 vaccines expressing spike-1, nucleocapsid, and RdRp antigens in murine models. We show that single-dose intranasal immunization, particularly with chimpanzee Ad-vectored vaccine, is superior to intramuscular immunization in induction of the tripartite protective immunity consisting of local and systemic antibody responses, mucosal tissue-resident memory T cells and mucosal trained innate immunity. We further show that intranasal immunization provides protection against both the ancestral SARS-CoV-2 and two VOC, B.1.1.7 and B.1.351. Our findings indicate that respiratory mucosal delivery of Ad-vectored multivalent vaccine represents an effective next-generation COVID-19 vaccine strategy to induce all-around mucosal immunity against current and future VOC.

Gene fusions characterize a subset of uterine cellular leiomyomas.

Uterine leiomyomas are the most common benign tumor of the female genital tract. Previous studies have shown that conventional leiomyomas often harbor-specific alterations including rearrangements involving HMGA2. Cellular leiomyomas are a variant of uterine leiomyoma that are less well-studied from a genomic point of view. Morphologically and immunohistochemically, cellular leiomyomas may be confused with low-grade endometrial stromal neoplasms, a group of tumors which frequently harbor a number of recurrent gene fusions. Ancillary molecular testing may be used to investigate tumors where low-grade endometrial stromal neoplasms enter into the differential diagnosis. At our institution, we identified a uterine cellular leiomyoma harboring a HMGA2-TRAF3IP2 fusion. After a retrospective review 11 additional tumors were identified. All included cases were reviewed and evaluated for immunohistochemical expression of smooth muscle actin, desmin, h-caldesmon, CD10, estrogen receptor, and progesterone receptor. RNA sequencing using the TruSight RNA Fusion Panel was performed on formalin-fixed paraffin-embedded tissue samples. In addition to the index case, two other cases harbored fusions: HMGA2-NAA11 and TPCN2-YAP1, of which the latter is novel and was confirmed with reverse transcriptase-polymerase chain reaction. In conclusion, a subset of cellular leiomyomas harbor rearrangements involving HMGA2, suggesting molecular kinship with conventional uterine leiomyomas. In addition, the prevalence of the novel TPCN2-YAP1 gene fusion in cellular leiomyomas requires further study. The fusions reported here, when identified, may be useful when the diagnosis of cellular leiomyoma is in question.

Do deeper sections increase the frequency of detection of serous tubal intraepithelial carcinoma (STIC) in the "sectioning and extensively examining the FIMbriated end" (SEE-FIM) protocol?

Studies have suggested serous tubal intraepithelial carcinoma (STIC) of the fallopian tube to be a putative precursor to ovarian and peritoneal serous carcinoma. It has been recommended that resected fallopian tube specimens should be rigorously examined for STIC, especially in women at high risk of serous carcinoma, such as those with BRCA mutations or with a strong family history. The SEE-FIM protocol allows for the greatest surface area of the tube to be histologically assessed. There have been suggestions that multiple deeper sections should be examined if the initial hematoxylin and eosin (H&E) sections are negative; however, whether this identifies more cases of STIC has not rigorously examined. We examined deeper sections from 56 cases of pelvic carcinoma in which the initial H&E sections of the fallopian tubes were negative for STIC. All initial and deeper sections underwent consensus review by panel of experts in gynecologic pathology. These cases are part of a larger study in which we had examined 300 consecutive bilateral salpingectomies using the SEE-FIM protocol and a single-H&E section per block and had identified 68 cases of pelvic serous carcinoma, of which 12 were associated with STIC. We calculated the sensitivity of a single-H&E section to detect STIC, as compared with examination of multiple deeper sections, and reevaluated the clinicopathologic data of the parent study in light of the additional cases of STIC. In the 56 cases initially negative for STIC, 4 cases of STIC were identified after examination of multiple deeper sections of the fallopian tubes. The single-H&E section SEE-FIM approach therefore detected only 75% (95% confidence interval, 51%-90%) of STIC that was present. Three of these new cases were associated with primary ovarian serous carcinoma and 1 with primary peritoneal serous carcinoma. All 3 new cases associated with ovarian carcinoma were noted in women without neoadjuvant chemotherapy. In considering the data from the parent study, we calculated a statistically significant lower incidence of STIC in women with ovarian serous carcinoma who received neoadjuvant chemotherapy as compared with those who did not (P=0.042). Our study demonstrated that additional cases of STIC can be detected if deeper sections are examined. These additional cases also highlighted a statistically significant difference in the incidence of STIC associated with ovarian serous carcinoma who received neoadjuvant chemotherapy relative to those who did not. Consideration to this should be given in future studies of the prevalence of STIC and to routine examination of salpingectomy specimens from women at high risk for pelvic serous carcinoma.

Pembrolizumab-induced immune-related sclerosing cholangitis.

Immunotherapy is increasingly used to treat various types of cancer; however, it can often result in immune-related adverse events (irAEs). Immune-related sclerosing cholangitis (irSC) is a rare type of hepatic irAE that has been described only in a few cases, and much remains unknown about its optimal treatment. In this report, we describe the case of a man in his 70s who was diagnosed with metastatic melanoma and treated with pembrolizumab. He experienced multiple irAEs, including irSC, which did not respond to initial prednisone treatment (2 mg/kg daily dosing). However, subsequent treatment with ursodeoxycholic acid (UDCA) resulted in complete resolution of symptoms and normalisation of laboratory and radiographic abnormalities related to irSC. Our case suggests that steroids, which are traditionally used to treat irAEs, may be ineffective for irSC and that UDCA may be a better alternative. Clinicians should be aware of this rare irAE.

Interferon-λ mediates oral tolerance and inhibits antigen-specific, T-helper 2 cell-mediated inflammation in mouse intestine.

BACKGROUND & AIMS: Oral tolerance is an important component of gastrointestinal homeostasis, but mechanisms of its development are not fully understood. Loss of oral tolerance occurs during food allergen-related inflammation in the gastrointestinal tract. Interferon (IFN)-λ regulates immunity, but its role in oral tolerance is not clear. We investigated the role and the mechanism of IFN-λ in the development of oral tolerance and its effect on antigen-induced, T-helper (Th)-2 cell-mediated inflammation in the intestine. METHODS: Expression of IFN-λ and its receptor were analyzed by immunohistochemical, flow cytometric, or immunoblot analyses. Tolerogenic dendritic cells (DCs) and regulatory T cells were examined in vitro and in vivo. A mouse model of antigen-induced, Th2 cell-mediated intestinal inflammation was used to examine the role of IFN-λ and T cells in oral tolerance in the intestine. RESULTS: CD3+ cells expressed the IFN-λ receptor, which was up-regulated following antigen-specific or nonspecific activation. Interaction between IFN-λ and its receptor induced apoptosis of T cells and their subsequent phagocytosis by DCs. This led to the generation of tolerogenic DCs and T regulatory cells in vitro and in vivo. Passive transfer of IFN-λ-primed CD3+ cells inhibited Th2 cell-mediated inflammation in the intestine. CONCLUSIONS: IFN-λ is involved in development and maintenance of oral tolerance in the intestines of mice; it might be used to suppress antigen-specific Th2 cell-mediated inflammation in patients.

Frequency of serous tubal intraepithelial carcinoma in various gynecologic malignancies: a study of 300 consecutive cases.

Serous tubal intraepithelial carcinoma (STIC) has been implicated in the pathogenesis of pelvic serous carcinoma. We hypothesized that, if this is the case, the frequency of STIC should be substantially lower in endometrial serous carcinomas, in nonserous gynecologic malignancies, and in benign gynecologic neoplasms than in ovarian or peritoneal serous carcinomas. From 2007 to 2009 the fallopian tubes of 342 consecutive gynecologic cases were entirely submitted for histology using the Sectioning and Extensively Examining the FIMbriated end protocol. This study included 300 of these cases (277 TAH-BSO, 23 BSO) after exclusion. The hematoxylin and eosin-stained slides from the fallopian tubes were independently reviewed by 2 gynecologic pathologists who were blinded to all other findings; disagreements were resolved by a third pathologist. Among 46 cases of ovarian malignancies, STIC was identified in 6 (18.8%) of 32 cases of serous carcinoma, but not in any other subtype. Similarly, STIC coexisted in 4 (14.3%) of 28 cases of endometrial serous carcinoma; however, no STIC was identified in any of the 74 cases of nonserous endometrial malignancies. STIC was identified in 2 (28.6%) of 7 cases of peritoneal serous carcinoma. No STIC was identified among 15 nongynecologic malignancies, 90 cases of benign conditions, and 27 cases of other conditions including 4 cases of cervical adenocarcinoma in situ and high-grade cervical intraepithelial lesions, 8 cases of endometrial atypical complex hyperplasias, and 15 cases of ovarian borderline tumors. In conclusion, the fallopian tube may be the origin of some pelvic serous carcinomas. Other possibilities that may explain the origin of pelvic high-grade serous carcinoma are discussed. Given that STIC coexisted with 14% of endometrial serous carcinomas, a more unifying theory may be that gynecologic serous carcinomas and STIC are multifocal lesions.

Comparing Current and Next-Generation Humanized Mouse Models for Advancing HIV and HIV/Mtb Co-Infection Studies.

In people living with HIV, Mycobacterium tuberculosis (Mtb) is the major cause of death. Due to the increased morbidity/mortality in co-infection, further research is urgently required. A limiting factor to research in HIV and HIV/Mtb co-infection is the lack of accessible in vivo models. Next-generation humanized mice expressing HLA transgenes report improved human immune reconstitution and functionality, which may better recapitulate human disease. This study compares well-established huNRG mice and next-generation HLA I/II-transgenic (huDRAG-A2) mice for immune reconstitution, disease course, and pathology in HIV and TB. HuDRAG-A2 mice have improved engraftment of key immune cell types involved in HIV and TB disease. Upon intravaginal HIV-1 infection, both models developed significant HIV target cell depletion in the blood and tissues. Upon intranasal Mtb infection, both models sustained high bacterial load within the lungs and tissue dissemination. Some huDRAG-A2 granulomas appeared more classically organized, characterized by focal central necrosis, multinucleated giant cells, and foamy macrophages surrounded by a halo of CD4+ T cells. HIV/Mtb co-infection in huNRG mice trended towards worsened TB pathology and showed potential for modeling co-infection. Both huNRG and huDRAG-A2 mice are viable options for investigating HIV and TB, but the huDRAG-A2 model may offer advantages.

Fc gamma receptor signaling in mast cells links microbial stimulation to mucosal immune inflammation in the intestine.

Microbes and microbial products are closely associated with the pathogenesis of inflammatory bowel disease (IBD); however, the mechanisms behind this connection remain unclear. It has been previously reported that flagellin-specific antibodies are increased in IBD patient sera. As mastocytosis is one of the pathological features of IBD, we hypothesized that flagellin-specific immune responses might activate mast cells that then contribute to the initiation and maintenance of intestinal inflammation. Thirty-two colonic biopsy samples were collected from IBD patients. A flagellin/flagellin-specific IgG/Fc gamma receptor I complex was identified on biopsied mast cells using both immunohistochemistry and co-immunoprecipitation experiments; this complex was shown to co-localize on the surfaces of mast cells in the colonic mucosa of patients with IBD. In addition, an ex vivo study showed flagellin-IgG was able to bind to human mast cells. These cells were found to be sensitized to flagellin-specific IgG; re-exposure to flagellin induced the mast cells to release inflammatory mediators. An animal model of IBD was then used to examine flagellin-specific immune responses in the intestine. Mice could be sensitized to flagellin, and repeated challenges with flagellin induced an IBD-like T helper 1 pattern of intestinal inflammation that could be inhibited by pretreatment with anti-Fc gamma receptor I antibodies. Therefore, flagellin-specific immune responses activate mast cells in the intestine and play important roles in the pathogenesis of intestinal immune inflammation.

Immunoglobulin kappa and immunoglobulin lambda are required for expression of the anti-apoptotic molecule Bcl-xL in human colorectal cancer tissue.

OBJECTIVE: Aberrant expression of immunoglobulin (Ig) by cancer cells has been documented in a number of malignant tumors but its biological significance is unclear. Cancer cells overexpress anti-apoptotic molecules such as Bcl-xL. The present study aimed to examine the role of expression of Ig light-chain Igk and Iglambda in maintaining the high levels of Bcl-xL in colorectal cancer cells. MATERIAL AND METHODS: Thirty patients with colorectal cancer were recruited to this study. Expression of Igk, Iglambda and Bcl-xL in surgically removed cancer tissue was examined by immunohistochemistry and/or flow cytometry. Using the HT29 cell line as a study platform, RNA interference (RNAi) was employed to knock out the genes of Igk and Iglambda in the cancer cell line; the expression of Bcl-xL in HT29 cells was subsequently analyzed. RESULTS: Human colorectal cancer cells, but not normal colorectal tissue, expressed both Igk and Iglambda in the cytoplasm. High levels of Bcl-xL were detected in cancer cells. Using RNAi to knock out the genes of Igk and/or Iglambda, Bcl-xL expression in HT29 cells was significantly suppressed and the cells became apoptotic. CONCLUSION: The results suggest that expression of Igk and Iglambda is required to stabilize Bcl-xL expression in cancer cells.

Amelanotic Melanoma Presenting with Plasmacytoid Morphology and BRAF V600 Mutation.

Plasmacytoid melanoma is an unusual variant of malignant melanoma. The plasmacytoid morphology can be found in a variety of other malignancies including carcinomas, plasma cell neoplasms, lymphoproliferative disorders, and sarcomas. The authors report a rare case of plasmacytoid amelanotic malignant melanoma in a 78-year-old man presenting with an enlarging palpable, erythematous mass on his left posterior shoulder. A fine needle aspirate showed atypical findings with single amelanotic cells with high nuclear to cytoplasmic ratio, mono- and multi-nucleation with prominent nucleoli and intranuclear inclusions. Review of the excision and immunohistochemical analysis revealed the malignant plasmacytoid cells stained with vimentin, S-100, HMB-45, and other staining patterns consistent with melanoma. Initial evaluation was negative for other sites of disease. However, 4 months later, the patient was noted to have metastatic disease to his lungs and liver. Given that the tumor was noted to be BRAF V600R mutated, the patient was started on single agent dabrafenib. The plasmacytoid morphology can be found in a variety of malignancies. Melanoma should be considered in the differential diagnosis of any malignancy presenting with plasmacytoid features.

Interobserver agreement for assessing invasion in stage 1A vulvar squamous cell carcinoma.

Invasive squamous cell carcinoma of the vulva with ≤1 mm stromal invasion is classified as stage 1A. Cancer staging systems state that the depth of invasion should be measured from the epithelial-stromal junction of the adjacent most superficial dermal papilla to the deepest point of the invasive tumor. Measurement of the depth of invasion guides patient management. Even though this measurement is critical, no studies have reported the reliability among pathologists for determining the cutoff point of ≤1 mm stromal invasion in vulvar cancer. We assessed agreement among pathologists for determining whether a vulvar tumor is invasive, for the depth of invasion, and for tumor thickness. Forty-five cases of vulvar squamous cell carcinoma with a depth of invasion of ≤5 mm were chosen. Eleven gynecologic pathologists independently reviewed the slides and, for a subset of cases, pictorially recorded measurements on photographs. The number of cases that were reported as invasive by the 11 pathologists ranged from 21 to 44. The number of cases that were reported as showing a depth of invasion of ≤1 mm ranged from 7 to 27. Eight pathologists provided measurements for all lesions reported as invasive, the remaining 3 pathologists stated that they were unable to measure 2, 7, and 16 lesions, respectively. Mean κ for diagnosing vulvar carcinoma as invasive was 0.24 and for measuring the depth of invasion and thickness was 0.51 and 0.49, respectively. There was only fair agreement in determining whether the lesion was invasive. In cases in which pathologists agreed upon the diagnosis of invasion, agreement on depth was moderate. When using the recommended cancer staging method, interpretation of the location of the most superficial dermal papilla varied among pathologists. Measuring thickness did not improve agreement. This is the first study that has assessed the reliability of the diagnosis of invasion in vulvar cancer among gynecologic pathologists, the interobserver agreement for reporting the critical 1 mm threshold of depth of stromal invasion, and the way in which the International Federation of Gynecology and Obstetrics method is used by pathologists.

Littoral cell angioma: diagnosis by image-guided biopsy.

We report a case of littoral cell angioma (LCA) diagnosed by percutaneous core needle biopsy during the workup of a patient with multiple splenic lesions. Splenectomy was not performed. The patient has remained asymptomatic during 4 years of follow-up. Our findings raise interesting questions about the feasibility of core needle biopsy for the diagnosis of LCA. Clinicians should be aware of LCA as an unusual benign entity in the differential diagnosis of multiple splenic lesions.

Expression of integrin alphavbeta6 in the intestinal epithelial cells of patients with inflammatory bowel disease.

BACKGROUND AND AIMS: The prevalence of inflammatory bowel disease (IBD) is about 0.05% in industrialized countries. The pathogenesis of IBD remains to be further understood. The present study aims to elucidate the expression of integrin αvß6 in the intestinal mucosa of patients with IBD. MATERIALS AND METHODS: Colonic biopsy was obtained from a group of IBD patients. The expression of αvß6 in the intestinal mucosa was detected by Western blotting. Human colonic epithelial cell line T84 cells were stimulated by microbial antigen flagellin. The expression of αvß6 in T84 cells was evaluated by quantitative RT-PCR and Western blotting. RESULTS: The levels of αvß6 in the intestinal mucosa were much lower than it in normal control subjects. The serum levels of myeloperoxidase (MPO) were higher in IBD patients that were negatively correlated with the levels of αvß6 in the intestinal mucosa. The expression of αvß6 was detectable in T84 cells at naοve status that could be upregulated by exposure to microbial antigen flagellin. Pretreatment with MPO dramatically suppressed the expression of αvß6 in T84 cells. CONCLUSIONS: We conclude that the expression of αvß6 was suppressed in IBD intestinal mucosa, which could be resulted from the high levels of MPO.

Borderline Phyllodes Tumor with an Incidental Invasive Tubular Carcinoma and Lobular Carcinoma In Situ Component: A Case Report / 한국유방암학회지

Phyllodes tumors are an infrequent breast tumor presentation. A phyllodes tumor with a synchronous invasive ductal carcinoma is rarely described and has never been reported with lobular carcinoma in situ component. A 53-year-old female presented with a nine-year history of twice core biopsy proven fibroadenoma. After an increase in the tumor's growth velocity it was decided upon to undergo an excisional biopsy. Microscopic examination of the well-circumscribed pale-tan mass found focal areas of leaf like architecture with variable number of mitoses present, representing a phyllodes tumor of borderline malignant potential. Incidentally, at one edge of the mass was found a tubular carcinoma and lobular carcinoma in situ components. Thorough, routine follow-up of patients with biopsy proven benign breast masses is important to finding a masked malignant component.