Early changes in soluble intracellular adhesion molecule-1 as prognostic biomarkers to immune checkpoint inhibitor

Serologic biomarker to predict clinical outcome is needed for immune checkpoint inhibitors (ICIs). We evaluated soluble intercellular adhesion molecules-1 (sICAM-1) as a predictor of response to ICIs treatment. Ninety-five patients with cancer treated with ICI were studied. The serum sICAM-1 levels of baseline, post two cycle therapy and end of therapy (EOT) were measured by enzyme-linked immunoassay. We randomly assigned the patients into the primary cohort (n = 47) and validation cohort (n = 48). Serum sICAM-1 post two cycle (277.7 ± 181.6 ng/mL) and EOT (403.9 ± 218.9 ng/mL) were significantly elevated compared to baseline (244.8 ± 153.8 ng/mL, p = 0.008 and p = 0.004, respectively). Early changes of sICAM-1 (ΔsICAM-1), deemed as sICAM-1 after two cycles minus baseline, were assessed. Following ICI treatments, responders had significantly lower ΔsICAM-1 compared with nonresponders in the primary cohort (p = 0.040) and the validation cohort (p = 0.026). High ΔsICAM-1 was strongly associated with inferior progression-free survival (PFS; (primary cohort: p = 0.001 and validation cohort: p = 0.002) and overall survival (OS; (primary cohort: p < 0.001 and validation cohort: p = 0.007). The ΔsICAM-1 remained independently associated with worse PFS and OS in the primary cohort and the validation cohort. Subgroup analysis indicated patients whose sICAM-1 significantly elevated had shorter PFS and OS in both anti-PD-1 and anti-PD-L1 treatment groups. Early change of serum sICAM-1 could be used to monitor and predict clinical benefit of ICI therapy in patients with solid cancer.

Adaptive and Innate Cytotoxic Effectors in Chronic Lymphocytic Leukaemia (CLL) Subjects with Stable Disease

Chronic lymphocytic leukaemia (CLL) is characterised by the expansion of a neoplastic mature B cell clone. CLL clinical outcome is very heterogeneous, with some subjects never requiring therapy and some showing an aggressive disease. Genetic and epigenetic alterations and pro-inflammatory microenvironment influence CLL progression and prognosis. The involvement of immune-mediated mechanisms in CLL control needs to be investigated. We analyse the activation profile of innate and adaptive cytotoxic immune effectors in a cohort of 26 CLL patients with stable disease, as key elements for immune-mediated control of cancer progression. We observed an increase in CD54 expression and interferon (IFN)-γ production by cytotoxic T cells (CTL). CTL ability to recognise tumour-targets depends on human leukocyte antigens (HLA)-class I expression. We observed a decreased expression of HLA-A and HLA-BC on B cells of CLL subjects, associated with a significant reduction in intracellular calnexin that is relevant for HLA surface expression. Natural killer (NK) cells and CTL from CLL subjects show an increased expression of the activating receptor KIR2DS2 and a reduction of 3DL1 and NKG2A inhibiting molecules. Therefore, an activation profile characterises CTL and NK cells of CLL subjects with stable disease. This profile is conceivable with the functional involvement of cytotoxic effectors in CLL control.

CD18 in monogenic and polygenic inflammatory processes of the skin

The beta 2 integrin family (CD11/CD18) of leukocyte adhesion molecules plays a key role in inflammation. Absence of the common chain (CD18) leads to leukocyte adhesion deficiency-1 (LAD1) in humans. We here summarize data of two genetically defined mice models of beta 2 integrin deficiency, one with a CD18 null mutation (CD18-/-), and the other one with a hypomorphic CD18 mutation (CD18hypo). Firstly, we focus on the underlying mechanism of a severely impaired wound healing in CD18-/- mice, outlining a scenario in which a defective extravasation and phagocytosis of CD18-/- neutrophils results in delayed myofibroblast-dependent wound contraction owing to a deficient transforming growth factor-beta 1 release. Based on this, we have identified a potential therapy that fully rescued the impaired wound healing in CD18-/- mice. Secondly, we expand on a CD18hyp0 PL/J mouse model closely resembling human psoriasis. Apart from common clinical and pathophysiological features, this psoriasiform dermatitis also depends on the presence of activated CD4+ T cells. We here recapitulate the influence of a reduced CD18 gene expression on T-cell function, also with regard to CD18 gene-dose effects, and its contribution to the pathogenesis of this disease. Taken together, these unique features make this model a valuable tool for investigations into the pathogenesis of human psoriasis--including its polygenic base--and future preclinical studies.

Nematode Infection Enhances Survival of Activated T Cells by Modulating Accessory Cell Function

The type of immune response generated following exposure to Ag depends on a variety of factors, including the nature of the Ag, the type of adjuvant used, the site of antigenic entry, and the immune status of the host. We have previously shown that infection of rodents with Nippostrongylus brasiliensis (Nb) shifts the development of type 1 allo-specific responses toward type 2 immunity, suggesting nematode modulation of T cell activation. In this report we explore the immunomodulatory effects of Nb on T cell activation. We found that spleen cells from Nb-infected mice exhibited dramatically increased proliferation in response to Con A and anti-CD3. This hyperproliferation could be transferred in vitro to naive splenocytes by coculture with mitomycin C-treated cells from Nb-infected animals. The transfer was mediated by non-T accessory cells and supernatants derived from Con A-activated non-T cells, suggesting the involvement of a soluble factor secreted by accessory cells. The accessory cells secreted high levels of IL-6, and anti-IL-6 treatment abrogated the supernatant-induced hyperproliferation, thus confirming that IL-6 was mediating the effect. Further, spleen cells from Nb-infected mice were more resistant to activation-induced cell death (AICD) following mitogenic stimulation. Reduced AICD was also transferable and IL-6 dependent. Thus, the hyperproliferation was in part due to enhanced activated T cell survival. These phenomena mediated by accessory cells may contribute to the powerful polyclonal activation of type 2 immunity caused by nematode infection.

The Dependence for Leukocyte Function-Associated Antigen-1/ICAM-1 Interactions in T Cell Activation Cannot Be Overcome by Expression of High Density TCR Ligand

The leukocyte-specific integrin, LFA-1, can enhance T cell activation. However, it is unclear whether the binding of LFA-1 to its ligand, ICAM-1, functions through intercellular adhesion alone, resulting in an augmentation of the TCR signal, or involves an additional LFA-1-mediated cellular signal transduction pathway. We have previously shown that naive CD4+ lymph node T cells, isolated from DO11.10 TCR transgenic mice, are activated by increasing doses of exogenous OVA peptide presented by transfectants expressing both class II and ICAM-1, but not by cells expressing class II alone. To determine whether LFA-1/ICAM-1 interactions were simply enhancing the presentation of low concentrations of specific MHC/peptide complexes generated from exogenously added peptide, we transfected cells with class II that is covalently coupled to peptide, alone or in combination with ICAM-1. These cells express 100-fold more specific class II/peptide complexes than can be loaded onto class II-positive cells at maximum concentrations of exogenous peptide. Despite this high density of TCR ligand, activation of naive CD4+ T cells still requires the coexpression of ICAM-1. LFA-1/ICAM-1 interactions are not required for effective conjugate formation and TCR engagement because presentation of class II/peptide complexes in the absence of ICAM-1 does induce up-regulation of CD25 and CD69. Thus, high numbers of engaged TCR cannot compensate for the lack of LFA-1/ICAM-1 interactions in the activation of naive CD4+ T cells.