Ruxolitinib inhibits IFNγ-stimulated Sjögren's salivary gland MSC HLA-DR expression and chemokine-dependent T cell migration

OBJECTIVES

Sjögren's disease (SjD) is a systemic autoimmune disease characterized by focal lymphocytic infiltrate of salivary glands (SGs) and high SG IFNγ, both of which are associated with elevated lymphoma risk. IFNγ is also biologically relevant to mesenchymal stromal cells (MSCs), a SG resident cell with unique niche regenerative and immunoregulatory capacities. In contrast to the role of IFNγ in SjD, IFNγ promotes an anti-inflammatory MSC phenotype in other diseases. The objective of this study was to define the immunobiology of IFNγ-exposed SG-MSCs with and without the JAK1 & 2 inhibitor, ruxolitinib.

METHODS

SG-MSCs were isolated from SjD and controls human subjects. SG-MSCs were treated with 10 ng/ml IFNγ +/- 1000 nM ruxolitinib. Experimental methods included flow cytometry, RNA-sequencing, chemokine array, ELISA and transwell chemotaxis experiments.

RESULTS

We found that IFNγ promoted expression of SG-MSC immunomodulatory markers, including HLA-DR, and this expression was inhibited by ruxolitinib. We confirmed the differential expression of CXCL9, CXCL10, CXCL11, CCL2 and CCL7, initially identified with RNA sequencing. SG-MSCs promoted CD4+ T cell chemotaxis when pre-stimulated with IFNγ. Ruxolitinib blocks chemotaxis through inhibition of SG-MSC production of CXCL9, CXCL10 and CXCL11.

CONCLUSIONS

These findings establish that ruxolitinib inhibits IFNγ-induced expression of SG-MSC immunomodulatory markers and chemokines. Ruxolitinib also reverses IFNγ-induced CD4+ T cell chemotaxis, through inhibition of CXCL9, -10 and -11. Because IFNγ is higher in SjD than control SGs, we have identified SG-MSCs as a plausible pathogenic cell type in SjD. We provide proof of concept supporting further study of ruxolitinib to treat SjD.

[Clinical characteristics and T-lymphocyte subsets in 48 acquired immune deficiency syndrome patients with cytomegalovirus infections]

Objective: To investigate the clinical features and T lymphocytes subsets in patients with acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) infection. Methods: A total of 48 hospitalized patients with human immunodeficiency virus (HIV)-1/AIDS and CMV infections were recruited at Peking Union Medical College Hospital from Jan 2010 to Aug 2017. Their clinical features and immune function were retrospectively analyzed. Patients with only HIV/AIDS in previous study were recruited as controls. Results: All 48 patients were at C3 stage, including 36 men and 12 women. Five of them were younger than 30 years old, 33 cases within 31-50 years old, and 10 cases older than 50 years old. Thirty-five patients had CD(4)(+)T lymphocytes ≤ 50 cells/μl, 7 cases with CD(4)(+)T cells 51-100/μl, 3 cases with 101-200 cells/μl, and 3 cases over 200 cells/μl. As to CMV infections, there were 31 cases of CMV viremia, 1 case of CMV encephalitis, 1 case of CMV enteritis, 5 cases of CMV pneumonia, and 9 cases of CMV retinitis. Other opportunistic infections were also common including 16 cases of pneumocystis pneumonia, 9 cases of tuberculosis, 5 cases of syphilis, 18 cases of digestive tract fungal infections, 8 cases of pulmonary fungal infections, 2 cases of EB virus infections, 2 cases of HIV encephalopathy/progressive multifocal leukoencephalopathy (PML), 3 cases of cryptococcal meningitis, 1 case of toxoplasma infection. In group of both CMV and HIV/AIDS infections, 100% patients had inverted CD(4)(+)/CD(8)(+) ratio. The immune activation marker CD(8)(+)CD(38)(+)/CD(8)(+) was higher (61.6%-98.8%) with a median value of 91.2% in 40 patients. HLA-DR(+)CD(8)(+)/CD(8)(+), another marker for T cell activation, was 25.5%-98.0% in 44 patients with a median value of 60.3%. Thirty-six patients had both immune activation markers positive. There was no significant difference in counts of B cells, natural killer cells, CD(4)(+) T cells, CD(8)(+) T cells and immune activation subsets stratified by gender and age (P>0.05). Meanwhile, neither serum HIV viral load nor serum CMV viral load was correlated with HLA-DR(+)CD(8)(+)/CD(8)(+), CD(8)(+)CD(38)(+)/CD(8)(+), CD(4)(+)T cell counts, and CD(4)(+)/CD(8)(+) ratio in the CMV and HIV/AIDS co-infection group (all P>0.05), while HIV viral load in HIV/AIDS only group was significantly correlated with HLA-DR(+)CD(8)(+)T/CD(8)(+), CD(38)(+)CD(8)(+)/CD(8)(+), CD(4)(+) T cell counts, CD(4)(+)/CD(8)(+) ratio (r=0.473, 0.575, -0.767 and -0.678, respectively, all P<0.05). Conclusions: CMV infections develop in HIV patients with advanced stage. CMV infection can cause life-threatening multiple organ lesions, especially in those with CD(4)(+) T cells less than 100 cells/μl. It is of great importance to screen CMV-IgM, pp65 antigen, CMV DNA to make early diagnosis and treatment.