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T cells are critical in mediating the early control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection. However, it remains unknown whether memory T cells can effectively cross-recognize new SARS-CoV-2 variants with a broad array of mutations, such as the emergent hypermutated BA.2.86 variant. Here, we report in two separate cohorts, including healthy controls and individuals with chronic lymphocytic leukemia, that SARS-CoV-2 spike-specific CD4+ and CD8+ T cells induced by prior infection or vaccination demonstrate resilient immune recognition of BA.2.86. In both cohorts, we found largely preserved SARS-CoV-2 spike-specific CD4+ and CD8+ T cell magnitudes against mutated spike epitopes of BA.2.86. Functional analysis confirmed that both cytokine expression and proliferative capacity of SARS-CoV-2 spike-specific T cells to BA.2.86-mutated spike epitopes are similarly sustained. In summary, our findings indicate that memory CD4+ and CD8+ T cells continue to provide cell-mediated immune recognition to highly mutated emerging variants such as BA.2.86.

Suboptimal immunity to SARS-CoV-2 mRNA vaccination has frequently been observed in individuals with various immunodeficiencies. Given the increased antibody evasion properties of emerging SARS-CoV-2 subvariants, it is necessary to assess whether other components of adaptive immunity generate resilient and protective responses against infection. We assessed T cell responses in 279 individuals, covering five different immunodeficiencies and healthy controls, before and after booster mRNA vaccination, as well as after Omicron infection in a subset of patients. We observed robust and persistent Omicron-reactive T cell responses that increased markedly upon booster vaccination and correlated directly with antibody titers across all patient groups. Poor vaccination responsiveness in immunocompromised or elderly individuals was effectively counteracted by the administration of additional vaccine doses. Functionally, Omicron-reactive T cell responses exhibited a pronounced cytotoxic profile and signs of longevity, characterized by CD45RA+ effector memory subpopulations with stem cell-like properties and increased proliferative capacity. Regardless of underlying immunodeficiency, booster-vaccinated and Omicron-infected individuals appeared protected against severe disease and exhibited enhanced and diversified T cell responses against conserved and Omicron-specific epitopes. Our findings indicate that T cells retain the ability to generate highly functional responses against newly emerging variants, even after repeated antigen exposure and a robust immunological imprint from ancestral SARS-CoV-2 mRNA vaccination.

BACKGROUND: We investigated whether sirolimus-based immunosuppression improves outcomes in liver transplantation (LTx) candidates with hepatocellular carcinoma (HCC). METHODS: In a prospective-randomized open-label international trial, 525 LTx recipients with HCC initially receiving mammalian target of rapamycin inhibitor-free immunosuppression were randomized 4 to 6 weeks after transplantation into a group on mammalian target of rapamycin inhibitor-free immunosuppression (group A: 264 patients) or a group incorporating sirolimus (group B: 261). The primary endpoint was recurrence-free survival (RFS); intention-to-treat (ITT) analysis was conducted after 8 years. Overall survival (OS) was a secondary endpoint. RESULTS: Recurrence-free survival was 64.5% in group A and 70.2% in group B at study end, this difference was not significant (P = 0.28; hazard ratio [HR], 0.84; 95% confidence interval [95% CI], 0.62; 1.15). In a planned analysis of RFS rates at yearly intervals, group B showed better outcomes 3 years after transplantation (HR, 0.7; 95% CI, 0.48-1.00). Similarly, OS (P = 0.21; HR, 0.81; 95% CI, 0.58-1.13) was not statistically better in group B at study end, but yearly analyses showed improvement out to 5 years (HR, 0.7; 95% CI, 0.49-1.00). Interestingly, subgroup (Milan Criteria-based) analyses revealed that low-risk, rather than high-risk, patients benefited most from sirolimus; furthermore, younger recipients (age ≤60) also benefited, as well sirolimus monotherapy patients. Serious adverse event numbers were alike in groups A (860) and B (874). CONCLUSIONS: Sirolimus in LTx recipients with HCC does not improve long-term RFS beyond 5 years. However, a RFS and OS benefit is evident in the first 3 to 5 years, especially in low-risk patients. This trial provides the first high-level evidence base for selecting immunosuppression in LTx recipients with HCC. TRIAL REGISTRATION: ClinicalTrials.gov NCT00355862.

Liver transplantation (LT) for patients with human immunodeficiency virus type-1 (HIV-1) infection has been associated with poor outcome. However, after the introduction of the highly active antiretroviral therapy, short-term patient survival after LT has improved significantly. We examined the long-term outcome of HIV-1-positive patients who underwent LT. Medical records were analysed in nine HIV-1-positive LT patients who underwent LT from August 1998 to May 2012. Eight were known to be HIV-1 positive at the time of listing for LT and had end-stage liver disease (ESLD) due to hepatitis C. One patient had primary biliary cirrhosis, and primary HIV-1 infection was found at the date of LT. Seven of the nine patients remain alive to date. So far, three have survived more than 12 years after LT. The overall patient survival rate for both five and 10 years is 77.8%. Four patients experienced acute rejection and six acquired biopsy-confirmed HCV recurrence. HIV-1 replication was effectively blocked during follow-up in all patients. We conclude that long-term survival of HIV-1-positive patients after LT can be achieved. Our study suggests that LT can offer an effective treatment option in selected HIV-1 infected patients with ESLD

Liver transplantation (LT) for unresectable locally advanced primary liver tumours (aPLT) is associated with an inferior survival compared to other established indications. As organ shortage in most regions is the major factor limiting the transplant rate, a careful selection of patients accepted for LT is necessary. Thus, the majority of patients with aPLT's will not be considered for LT even though a significant proportion of them may benefit from the procedure. The purpose of this study was to find ways to optimise the selection criteria for LT to a Scandinavian population of patients with hepatocellular carcinoma (HCC) and to explore the effect of adjuvant treatment on hepatic malignancies. In the first study we performed a retrospective evaluation of our own series of patients (n = 55) with. cirrhosis and HCC that have undergone LT. Two-third of the patients did not meet the standard selection criteria defined as single tumour < 5 em or 5 3 tumours, none sized > 3 em. We found that the number of nodules, the histological grade and the cold ischemia time all were independent risk factors for recurrence. To identify patients with an acceptable prognosis after LT, we hypothetically tested what the outcome would have been if a modification of the standard selection criteria (5 2 tumours with total tumour diameter < 10 em) had been applied for these patients. We found that, although these criteria were less restrictive, the recurrence rate in that group was identical (28%) to the group that met the standard criteria. The effect of adjuvant systemic chemotherapy after LT is not thoroughly investigated. We have studied the effect of adriamycin with or without cyclosporine A (CsA) on chemically induced rat hepatomas transferred to the spleens of a syngenic rat strain. We found that the tumour morphology was of utmost importance for the outcome. In poorly differentiated tumours, adriamycin exerted growth inhibition as expected, although partly counteracted by CsA. Howev

Background In histocompatibility mismatched experimental animals, a combination of T-cell-depleted autologous and allogeneic marrow may induce mixed chimerism and tolerance. Patients with large primary liver tumors have a poor outcome. We investigated whether it were possible to induce mixed chimerism and obtain an antitumor effect in a patient with a large primary liver cancer after combined liver and bone marrow transplantation (BMT). Methods A 46-year-old female with a primary non resectable liver cancer received a liver transplant from a cadaveric donor. Subsequently, she was conditioned with 4×2 Gy of total lymphoid irradiation, 120 mg/kg cyclophosphamide, and 7.5 Gy total body irradiation. Twelve days after liver transplantation, she received T-cell-depleted autologous : cadaveric 5/6 antigen HLA-mismatched marrow in a proportion of CD34+ cells of 0.5 : 3.0×106/kg. Chimerism status was determined with polymerase chain reaction amplification of variable number tandem repeats from DNA obtained from CD3+, CD19+, and CD45+ magnetic-bead-separated cells. Results The early posttransplant period was uneventful; liver function was normal and the hematopoietic engraftment of donor and recipient origin was prompt. [alpha]-fetoprotein levels dropped from 440 to 35 µg/l. One month after marrow transplantation, donor T-cells decreased markedly. Monoclonal antibody OKT-3 and 105/kg donor T-cells were given. One month later, the patient developed diarrhea and abdominal pain. A colonoscopy showed moderate gastrointestinal acute graft-versus-host disease and a Cryptosporidium infection. Three months after BMT, she became a complete donor chimera. Chimera cells showed little, if any, reactivity in mixed lymphocyte cultures to recipient and donor cells, but reacted to third party. Five months after BMT, she developed progressive Aspergillus fumigatus pneumonia and died. No tumor was found at the autopsy. Conclusion We obtained mixed donor-recipient hematopoietic chimerism withou