Studies on HIV-1 mucosal transmission to evaluate early events in pathogenesis and the development of effective preventive/prophylactic methods have thus far been hampered by the lack of a suitable animal model susceptible to HIV-1 infection by either vaginal and/or rectal routes. In this regard, while primate-SIV/SHIV and cat-FIV models provided useful surrogate platforms to derive comparative data, these viruses are distinct and different from that of HIV-1. Therefore an optimal model that permits direct study of HIV-1 transmission via mucosal routes is highly desirable. The new generation of humanized NOD/SCID BLT, NOD/SCIDgammac(-/-), and Rag2(-/-)gammac(-/-) mouse models show great promise to achieve this goal. Here, we show that humanized Rag2(-/-)gammac(-/-) mice (RAG-hu) engrafted with CD34 hematopoietic progenitor cells harbor HIV-1-susceptible human cells in the rectal and vaginal mucosa and are susceptible to HIV-1 infection when exposed to cell-free HIV-1 either via vagina or rectum. Infection could be established without any prior hormonal conditioning or mucosal abrasion. Both R5 and X4 tropic viruses were capable of mucosal infection resulting in viremia and associated helper T cell depletion. There was systemic spread of the virus with infected cells detected in different organs including the intestinal mucosa. R5 virus was highly efficient in mucosal transmission by both routes whereas X4 virus was relatively less efficient in causing infection. HIV-1 infection of RAG-hu mice by vaginal and rectal routes as shown here represents the first in vivo model of HIV-1 transmission across intact mucosal barriers and as such may prove very useful for studying early events in HIV-1 pathogenesis in vivo, as well as the testing of microbicides, anti-HIV vaccines/therapeutics, and other novel strategies to prevent HIV-1 transmission.
HIV is adept at avoiding naturally generated T cell responses; therefore, there is a need to develop HIV-specific T cells with greater potency for use in HIV cure strategies. Starting with a CD4-based chimeric antigen receptor (CAR) that was previously used without toxicity in clinical trials, we optimized the vector backbone, promoter, HIV targeting moiety, and transmembrane and signaling domains to determine which components augmented the ability of T cells to control HIV replication. This re-engineered CAR was at least 50-fold more potent in vitro at controlling HIV replication than the original CD4 CAR, or a TCR-based approach, and substantially better than broadly neutralizing antibody-based CARs. A humanized mouse model of HIV infection demonstrated that T cells expressing optimized CARs were superior at expanding in response to antigen, protecting CD4 T cells from infection, and reducing viral loads compared to T cells expressing the original, clinical trial CAR. Moreover, in a humanized mouse model of HIV treatment, CD4 CAR T cells containing the 4-1BB costimulatory domain controlled HIV spread after ART removal better than analogous CAR T cells containing the CD28 costimulatory domain. Together, these data indicate that potent HIV-specific T cells can be generated using improved CAR design and that CAR T cells could be important components of an HIV cure strategy.
Several new immunodeficient mouse models for human cell engraftment have recently been introduced that include the Rag2−/−γc−/−, NOD/SCID, NOD/SCIDγc−/− and NOD/SCIDβ2m−/− strains. Transplantation of these mice with CD34+ human hematopoietic stem cells leads to prolonged engraftment, multilineage hematopoiesis and the capacity to generate human immune responses against a variety of antigens. However, the various mouse strains used and different methods of engrafting human cells are beginning to illustrate strain specific variations in engraftment levels, duration and longevity of mouse life span. In these proof-of-concept studies we evaluated the Balb/c-Rag1−/−γ−/− strain for engraftment by human fetal liver derived CD34+ hematopoietic cells using the same protocol found to be effective for Balb/c-Rag2−/−γc−/− mice. We demonstrate that these mice can be efficiently engrafted and show multilineage human hematopoiesis with human cells populating different lymphoid organs. Generation of human cells continues beyond a year and production of human immunoglobulins is noted. Infection with HIV-1 leads to chronic viremia with a resultant CD4 T cell loss. To mimic the predominant sexual viral transmission, we challenged humanized Rag1−/−γc−/− mice with HIV-1 via vaginal route which also resulted in chronic viremia and helper T cell loss. Thus these mice can be further exploited for studying human pathogens that infect the human hematopoietic system in an in vivo setting.
HIV-1 infection is characterized by life-long viral persistence and continued decline of helper CD4 T cells. The new generation of humanized mouse models that encompass RAG-hu, hNOG and BLT mice have been shown to be susceptible to HIV-1 infection and display CD4 T cell loss. Productive infection has been demonstrated with both R5 and X4 tropic strains of HIV-1 via direct injection as well as mucosal exposure. However the duration of infection in these mice was evaluated for a limited time lasting only weeks post infection, and it is not established how long the viremia can be sustained, and if the CD4 T cell loss persists throughout the life of the infected humanized mice. In the present study we followed the HIV-1 infected RAG-hu mice to determine the long-term viral persistence and CD4 T cell levels. Our results showed that viremia persists life-long lasting for more than a year, and that CD4 T cell levels display a continuous declining trend as seen in the human. These studies provide a chronic HIV-1 infection humanized mouse model that can be used to dissect viral latency, long-term drug evaluation and immune-based therapies.
IMPORTANCE Same-day Mohs reconstructive surgery is not always possible owing to patient factors, scheduling, and complexity of defect, but there is hesitancy in delaying closure of such defects. OBJECTIVE To describe the frequency of and predictors of complications in patients undergoing delayed facial reconstruction after Mohs micrographic surgery (MMS).
Background Ambulatory care visits for chronic sinusitis outnumber visits for acute sinusitis. The majority of these visits are with non-otolaryngologists. In order to better understand patients diagnosed with chronic sinusitis by non-otolaryngologists, we sought to determine if incident cases of chronic sinusitis diagnosed by primary care (PC) or emergency medicine (EM) providers meet diagnostic criteria. Methods Retrospective cohort. Patients were identified using administrative data, 2005–2006. The dataset was then clinically annotated based on chart review. We excluded prevalent cases. Results We identified 114 patients with newly diagnosed chronic sinusitis in EM (75) or PC settings (39). Rhinorrhea (EM 61%, PC 59%) and nasal obstruction (EM 67%, PC 64%) were common in both settings but facial fullness (EM 80%, PC 39%) and pain (EM 40%, PC 18%) were more common in the EM setting. Few patients reported symptoms of 90 days or longer (EM 6.0%, PC 24%) and no patient had evidence of inflammation on physical examination. A minority of patients received a sinus CT scan (22.8%) or nasal endoscopy (1.8%). In total only 1 patient diagnosed with chronic sinusitis met the diagnostic criteria. Conclusions Most patients diagnosed with chronic sinusitis by non-otolaryngologists do not have the condition. Caution should be used in studying chronic sinusitis using administrative data from non-otolaryngology providers as a large proportion of the patients may not actually have the disease.
Introduction We aim to better characterize the staining patterns of inverted papilloma (IP) with and without carcinoma by performing immunohistochemistry for p16, EGFR (Epidermal Growth Factor Receptor), p53, and Cyclin D1 antibodies on a large patient cohort. Methods One hundred and sixty-two IP specimens from 122 patients treated at the University of Michigan between 1996 and 2011. Twenty-two specimens contained carcinoma. Tumor was extracted for construction of two tissue microarrays and stained for p16, EGFR, p53, and Cyclin D1. Tumor staining intensity and percentage staining were scored. Results Mean percentage staining for IP and IP with carcinoma was 12% versus 7% for p16 (no statistical significance, NS), 20% versus 34% for EGFR (NS), 4% versus 24% for p53 (p<0.001), and 17% versus 21% for Cyclin D1 (NS). Benign disease was positive for p16 in 64%, EGFR in 50%, p53 in 30%, and Cyclin D1 in 76%. Inverted papilloma with carcinomatous degeneration was positive for p16 in 14%, EGFR in 71%, p53 in 62%, and Cyclin D1 in 76%. This is statistically significant for differences between IP and IP carcinoma for p16 and p53 staining only. Conclusion Important characteristic staining pattern for inverted papilloma with and without carcinoma are highlighted in this study. Unlike recent trends in HPV-related head and neck malignancies, low expression of p16 is a marker for malignancy in this series. Positive staining for p53 correlates with the development of carcinoma in inverted papilloma.
Objectives and Hypothesis Our objectives were to characterize the quality of acute sinusitis care and to identify non-clinical factors associated with antibiotic use for acute sinusitis. We hypothesized that we would identify provider level factors associated with antibiotic use. Study Design Retrospective cohort at a single academic institution. Methods We developed and clinically annotated an administrative dataset of adult patients diagnosed with acute sinusitis between January 1, 2005 and December 31, 2006. We used identify factors associated with receipt of antibiotics. Results We find that 66.0% of patients with mild symptoms of short duration are given antibiotics and that non-clinical factors, including the individual provider, the provider's specialty, and the presence of a medical trainee, significantly influence antibiotic use. Relative to internal medicine providers, family medicine providers use fewer antibiotics and emergency medicine providers use more antibiotics for acute sinusitis. Conclusions Antibiotics continue to be over used for patients with mild acute sinusitis of short duration. Non-clinical characteristics, including the individual provider, the provider's specialty, and the presence of a medical trainee significantly influence use of antibiotics for acute sinusitis.
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