Epidermotropic CXCR3 positive marginal zone lymphoma: a distinctive clinical histopathological entity potentially originating in the skin; it does not always indicate splenic marginal zone lymphoma.

Epidermotropic B cell lymphoma represents a rare form of marginal zone lymphoma presenting as a disseminated skin rash resembling pityriasis rosea. To date there are 8 reported cases. In addition to the widespread nature of the skin rash, there is a proclivity for spleen and bone marrow involvement raising consideration regarding its categorization as a systemic lymphoma. We present an 89-year-old man with epidermotropic B cell lymphoma, who presented with a pityriasis rosea-like skin rash. An initial diagnosis of diffuse large cell B cell lymphoma was made based on the extent of dermal-based large cell infiltration. However, after recognizing the epidermotropic component and the distinctive clinical presentation, a diagnosis of epidermotropic B cell lymphoma was rendered. There was minimal bone marrow involvement based only on flow cytometric analysis, but there was no apparent bone marrow or splenic involvement on routine light microscopic assessment. Remission was = achieved with single agent rituximab chemotherapy and the patient remained symptom free. The neoplastic CD20 positive epidermotropic B lymphocytes expressed CXCR3. Similar to the prior reported cases by the authors, the neoplastic cells expressed CXCR3, a chemokine whose organ and tissue specific ligands could contribute to its relatively indolent clinicalcourse.

Expression of CCR3 and CCR4 Suggests a Poor Prognosis in Mycosis Fungoides and Sézary Syndrome.

Tumor cells in cutaneous T-cell lymphoma express limited numbers of chemokine receptors. We investigated the expression patterns of CXCR3, CCR3, CCR4 and CCR10 in mycosis fungoides, Sézary syndrome, lym-phomatoid papulosis and anaplastic large cell lymphoma in 121 skin biopsy samples. CXCR3 was expressed in 86% of mycosis fungoides cases but in no anaplastic large cell lymphoma cases. CCR3 was expressed in 73% of cases of CD30+ lymphoproliferative disorders such as lymphomatoid papulosis and anaplastic large cell lymphoma. Mycosis fungoides/Sézary syndrome patients with high CCR3 or CCR4 expression had a poorer survival prognosis than mycosis fungoides/Sézary syndrome patients whose tumor cells did not express these receptors. CCR10 was expressed in 50% of mycosis fungoides/Sézary syndrome cases and in 13% of cases with CD30+ lym-phoproliferative disorders. These results suggest that differential patterns of CXCR3, CCR3, CCR4 and CCR10 expression are useful for the diagnosis of cutaneous T-cell lymphoma. Moreover, expression of CCR3 or CCR4 suggests a poor prognosis in mycosis fungoides/Sézary syndrome.

Intratumoral injection of IFN-ß induces chemokine production in melanoma and augments the therapeutic efficacy of anti-PD-L1 mAb.

Despite recent advances in treatment for melanoma patients through using immune checkpoint inhibitors, these monotherapies have limitations and additional treatments have been explored. Type I IFNs have been used to treat melanoma and possess immunomodulatory effects including enhancement of T-cell infiltration. T-cell plays a critical role in immune checkpoint therapies via restoration of effector functions and tumor infiltration by T-cells predicts longer survival in a variety of cancer types. Moreover, tumor-infiltrating T-cells are associated with the expression of chemokines such as CCL5 and CXCR3 ligands in tumor tissues. We therefore investigated whether intratumoral injection of IFN-ß induces the expression of CCL5 and CXCR3 ligands in melanoma cells and has additional antitumor effects when combined with anti-PD-L1 mAb treatment. IFN-ß treatment enhanced CD8+ T-cell infiltration into tumors and CCL5 and CXCR3 ligand expression. In vivo studies using a mouse model showed that monotherapy with IFN-ß, but not with anti-PD-L1 mAb, inhibited tumor growth in comparison to control. However, the therapeutic efficacy of IFN-ß was significantly enhanced by the addition of anti-PD-L1 mAb. This antitumor response of combination therapy was abrogated by anti-CD8 mAb and IFN-ß augmented the neoantigen-specific T-cell response of anti-PD-L1 mAb. Our findings suggest that IFN-ß induces the expression of CCL5 and CXCR3 ligands in melanoma, which could play a role in T-cell recruitment, and enhances the efficacy of anti-PD-L1 mAb treatment in a CD8-dependent manner.

A similar local immune and oxidative stress phenotype in vitiligo and halo nevus.

BACKGROUND: Vitiligo and halo nevus are two common T-cell-mediated skin disorders. Although autoimmunity has been suggested to be involved in both diseases, the relationship between vitiligo and halo nevus is not fully understood. OBJECTIVE: The aim of the current study was to investigate whether vitiligo and halo nevus share the same immunological and oxidative stress response. METHODS: Infiltrations of T cells, and expressions of chemokine receptors (CXCR3, CCR4, CCR5) and cytotoxic markers (Granzyme B, Perforin) in the lesions of vitiligo and halo nevus were examined by immunohistochemistry. Enzyme-linked immunosorbent assay was performed to analyze the expressions of chemokines in the serum samples and cytotoxic markers secreted by CD8+ T cells which were sorted from the peripheral blood mononuclear cells in healthy donors, vitiligo and halo nevus patients. Tissue levels of chemokine receptors and CXCR3 ligands in healthy controls, vitiligo patients and halo nevus patients were determined by qRT-PCR analysis. The percentages of CXCR3+ CD4+ T and CXCR3+ CD8+ T cells from the peripheral blood samples were examined by flow cytometry. Tissue and serum hydrogen peroxide (H2O2) concentrations were measured using H2O2 assay kit. RESULTS: Immunohistochemistry revealed a significant T-cell response, with pronounced dermal infiltrates of CD8+ T cells in vitiligo and halo nevus. The inflammatory cytotoxic markers such as Granzyme B and Perforin were also elevated in vitiligo and halo nevus, suggesting inflammatory responses in situ. By qRT-PCR and ELISA assay, we found significantly increased expressions of the chemokine receptor CXCR3 and its ligands, especially the accumulated CXCL10 in the skin lesions of vitiligo and halo nevus. Moreover, the level of H2O2, a key player involved in regulation of the immune response was significantly upregulated in the skin lesions of vitiligo and halo nevus. In addition, the increased H2O2 concentration correlated positively with CXCL10 level in skin lesions of vitiligo and halo nevus. CONCLUSIONS: These results demonstrate a H2O2-involved autoimmune phenotype in vitiligo and halo nevus, characterized by increased level of IFN-γ-inducible chemokine pair CXCL10-CXCR3, as well as a dense CD8+ T infiltration in the skin lesions, thus suggesting a similar pathogenesis of the two diseases.

Simian Immunodeficiency Virus Targeting of CXCR3+ CD4+ T Cells in Secondary Lymphoid Organs Is Associated with Robust CXCL10 Expression in Monocyte/Macrophage Subsets.

Glycosylation of Env defines pathogenic properties of simian immunodeficiency virus (SIV). We previously demonstrated that pathogenic SIVmac239 and a live-attenuated, quintuple deglycosylated Env mutant (Δ5G) virus target CD4+ T cells residing in different tissues during acute infection. SIVmac239 and Δ5G preferentially infected distinct CD4+ T cells in secondary lymphoid organs (SLOs) and within the lamina propria of the small intestine, respectively (C. Sugimoto et al., J Virol 86:9323-9336, 2012, https://doi.org/10.1128/JVI.00948-12). Here, we studied the host responses relevant to SIV targeting of CXCR3+ CCR5+ CD4+ T cells in SLOs. Genome-wide transcriptome analyses revealed that Th1-polarized inflammatory responses, defined by expression of CXCR3 chemokines, were distinctly induced in the SIVmac239-infected animals. Consistent with robust expression of CXCL10, CXCR3+ T cells were depleted from blood in the SIVmac239-infected animals. We also discovered that elevation of CXCL10 expression in blood and SLOs was secondary to the induction of CD14+ CD16+ monocytes and MAC387+ macrophages, respectively. Since the significantly higher levels of SIV infection in SLOs occurred with a massive accumulation of infiltrated MAC387+ macrophages, T cells, dendritic cells (DCs), and residential macrophages near high endothelial venules, the results highlight critical roles of innate/inflammatory responses in SIVmac239 infection. Restricted infection in SLOs by Δ5G also suggests that glycosylation of Env modulates innate/inflammatory responses elicited by cells of monocyte/macrophage/DC lineages.IMPORTANCE We previously demonstrated that a pathogenic SIVmac239 virus and a live-attenuated, deglycosylated mutant Δ5G virus infected distinct CD4+ T cell subsets in SLOs and the small intestine, respectively (C. Sugimoto et al., J Virol 86:9323-9336, 2012, https://doi.org/10.1128/JVI.00948-12). Accordingly, infections with SIVmac239, but not with Δ5G, deplete CXCR3+ CCR5+ CD4+ T (Th1) cells during the primary infection, thereby compromising the cellular immune response. Thus, we hypothesized that distinct host responses are elicited by the infections with two different viruses. We found that SIVmac239 induced distinctly higher levels of inflammatory Th1 responses than Δ5G. In particular, SIVmac239 infection elicited robust expression of CXCL10, a chemokine for CXCR3+ cells, in CD14+ CD16+ monocytes and MAC387+ macrophages recently infiltrated in SLOs. In contrast, Δ5G infection elicited only modest inflammatory responses. These results suggest that the glycosylation of Env modulates the inflammatory/Th1 responses through the monocyte/macrophage subsets and elicits marked differences in SIV infection and clinical outcomes.

Altered expression of CXCR3 and CCR6 and their ligands in HTLV-1 carriers and HAM/TSP patients.

Recruitment of leukocytes by chemokines and chemokine receptors to CNS plays a crucial role in the induction of inflammatory response in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). In the present study, chemokine and chemokine receptors involved in trafficking of lymphocytes to the CNS were measured in HAM/TSP patients, HTLV-1 asymptomatic carriers (ACs), and healthy controls. The PVL, CCR6, and CXCR3 mRNA expression, and CXCL9 and CXCL10 protein levels were measured in all subjects. The PVL of HAM/TSP patients was higher than that of ACs (P = 0.02). CCR6 expression was higher in HAM/TSP patients and in ACs compared to the healthy controls (P = 0.005 and P = 0.04, respectively). A significant difference was observed in CCR6 expression when a combination of HAM/TSP patients and ACs were compared to the healthy individuals (P = 0.005). Furthermore, there was a significantly lower CXCR3 expression between HAM/TSP and control groups (P = 0.001), and between the ACs and healthy controls (P = 0.001). However, the increased CXCR3 expression in ACs compared to HAM/TSP patients was not significant. Furthermore, the CXCL10 protein levels in HAM/TSP patients was higher than in controls (P = 0.012), and CXCL9 protein levels was also higher in the HAM/TSP and ACs groups than in the controls (P = 0.001 and P = 0.004, respectively). In conclusion, it seems that decreased expression of CXCR3 and higher expression of CCR6 were associated with HTLV-1 infection, what indicate that these alterations may favor virus dissemination but not disease manifestation.

Follicular helper T cells in peripheral blood of patients with rheumatoid arthritis. / Células T helper foliculares en sangre periférica de pacientes con artritis reumatoide.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by the presence of different autoantibodies such as rheumatoid factor (RF) and anti-citrullinated protein antibodies. CD4T cells expressing CXCR5, referred as follicular helper T cells (Tfh), collaborate with B cells to produce antibodies. Differential expression of CXCR3 and CCR6 within CD4+CXCR5+ T cells defines three mayor subsets: CXCR3+CCR6- (Tfh1), CXCR3-CCR6- (Tfh2) and CXCR3-CCR6+ (Tfh17). The aim of the study was to assess whether there is an association between the percentage of these cells and RA and whether there is a correlation with disease activity. MATERIAL AND METHODS: Twenty-four RA patients, 22 healthy controls (HC) and 16 undifferentiated arthritis (UA) patients were included. Percentage of CD4+CXCR5+ T cells and their subsets were analyzed by flow cytometry. RESULTS: No differences were found in the percentages of CD4+CXCR5+ T cells in the comparison of RA vs HC or RA vs UA patients. Tfh1, Tfh2 and Tfh17 subsets showed no differences either. There was no correlation between CD4+CXCR5+T cells, Tfh1, Tfh2 and Tfh17, and Disease Activity Score in twenty-eight joints (DAS28) or erythrocyte sedimentation rate. Surprisingly, there was a positive correlation between Tfh17 cells and C-reactive protein. Finally, there was no correlation between CD4+CXCR5+ T cells, or their subsets, and anti-mutated citrullinated vimentin, or between the cells and RF. CONCLUSION: There were no differences between the percentages of CD4+CXCR5+ T cells and their subsets in peripheral blood of RA patients and the percentages of cells in the control groups. This finding does not rule out a pathogenic role of these cells in the development and activity of RA.

Atrophying pityriasis versicolor as an idiosyncratic T cell-mediated response to Malassezia: A case series.

BACKGROUND: Atrophying pityriasis versicolor (PV), first described in 1971, is a rare variant in which lesions appear atrophic. OBJECTIVE: We sought to determine the pathophysiology of atrophying PV. METHODS: A retrospective chart review identified 6 cases of atrophying PV. In all cases, routine light microscopy, an elastic tissue stain, and immunohistochemical assessment for the expression of CD3, CD4, CD8, GATA3 and CXCR3 was performed. RESULTS: All cases demonstrated hyperkeratosis with intracorneal infiltration by pathogenic hyphal forms as well as epidermal attenuation and papillary dermal elastolysis. A supervening, mild-to-moderate, superficial lymphocytic infiltrate was noted and characterized by a focal CD8+ T cell-mediated interface dermatitis along with a mixed T-cell infiltrate composed of GATA3+ and CXCR3+ T cells. LIMITATIONS: Small sample size and the loss of some patients to follow-up. CONCLUSION: Atrophying PV represents the sequelae of a mixed helper T-cell (TH1 and TH2) idiosyncratic immune response to Malassezia and can present as a protracted dermatosis that may clinically mimic an atypical lymphocytic infiltrate. TH1 cytokines can recruit histiocytes, a source of elastases, and upregulate matrix metalloproteinase activity, which may contribute to epidermal atrophy.

Differential gene and protein expression of chemokines and cytokines in synovial fluid of patients with arthritis.

BACKGROUND: Psoriatic arthritis (PsA), an inflammatory musculoskeletal disease, develops in approximately 30% of patients with psoriasis. Previously, chemokine (C-X-C motif) ligand 10 (CXCL10) was identified as a predictive biomarker of PsA in patients with psoriasis and was reduced after development of PsA. The purpose of the present study was to explore messenger RNA (mRNA) and protein expression of CXCL10 and its receptor, chemokine (C-X-C motif) receptor 3 (CXCR3), in the joints of patients with PsA to gain insight into their role in the pathogenesis of the disease. METHODS: Sera from 47 patients with PsA and 33 healthy control subjects were compared for expression of CXCL10 by Luminex assay. Synovial fluid (SF) was obtained from patients with PsA (n = 40), osteoarthritis (OA; n = 14), gout (n = 8), and rheumatoid arthritis (RA; n = 11) during clinical care. SF mRNA and protein expression of CXCL10, interleukin-17A (IL-17A), CXCR3, TBX21, RORC and/or interferon γ (IFNγ) were compared among the above-mentioned disease groups, as well as in paired SF and serum samples from patients with PsA using real-time polymerase chain reaction and Luminex assays, respectively. RESULTS: Serum CXCL10 was significantly higher in patients with PsA than in control subjects (p = 0.0007). CXCL10, IL-17A, and TBX21 expression were elevated in SF cells of patients with PsA compared with those of patients with OA and gout, but not those of patients with RA. CXCR3 and RORC were elevated in PsA SF cells compared with all other patient groups. Concordant results were obtained for CXCL10 and IL-17A protein expression. IFNγ was elevated in PsA SF compared with OA SF (p = 0.015). CXCL10 protein expression was substantially increased in SF (median 7283.9 pg/ml, interquartile range [IQR] 1330-10,362 pg/ml) compared with paired serum samples (median 282.06, IQR 180.7-395.8 pg/ml; p = 0.001), whereas IFNγ was significantly reduced (SF median 6.03 pg/ml, IQR 4.47-8.94 pg/ml; versus serum median 23.70 pg/ml, IQR 3.2-104.6 pg/ml; p = 0.001). CONCLUSIONS: CXCL10 may have an important etiological role in PsA that is analogous to that in RA, and it is a candidate biomarker to distinguish PsA from healthy individuals and from patients with OA and gout.

New insights into the heterogeneity of Th17 subsets contributing to HIV-1 persistence during antiretroviral therapy.

BACKGROUND: Th17 cells are permissive to HIV-1 infection and their depletion from the gut of infected individuals leads to microbial translocation, a major cause for non-AIDS co-morbidities. Most recent evidence supports the contribution of long-lived Th17 cells to HIV persistence during antiretroviral therapy (ART). However, the identity of long-lived Th17 cells remains unknown. RESULTS: Here, we performed an in-depth transcriptional and functional characterization of four distinct Th17 subsets and investigated their contribution to HIV reservoir persistence during ART. In addition to the previously characterized CCR6(+)CCR4(+) (Th17) and CCR6(+)CXCR3(+) (Th1Th17) subsets, we reveal the existence of two novel CCR6(+) subsets, lacking (double negative, CCR6(+)DN) or co-expressing CXCR3 and CCR4 (double positive, CCR6(+)DP). The four subsets shared multiple Th17-polarization markers, a fraction of cells proliferated in response to C. albicans, and exhibited lineage commitment and plasticity when cultured under Th17 and Th1 conditions, respectively. Of note, fractions of CCR6(+)DN and Th17 demonstrated stable Th17-lineage commitment under Th1-polarization conditions. Among the four subsets, CCR6(+)DN expressed a unique transcriptional signature indicative of early Th17 development (IL-17F, STAT3), lymph-node homing (CCR7, CD62L), follicular help (CXCR5, BCL6, ASCL2), and self-renewal (LEFI, MYC, TERC). Cross sectional and longitudinal studies demonstrated that CCR6(+)DN cells were the most predominant CCR6(+) subset in the blood before and after ART initiation; high frequencies of these cells were similarly observed in inguinal lymph nodes of individuals receiving long-term ART. Importantly, replication competent HIV was isolated from CCR6(+)DN of ART-treated individuals. CONCLUSIONS: Together, these results provide new insights into the functional heterogeneity of Th17-polarized CCR6(+)CD4(+) T-cells and support the major contribution of CCR6(+)DN cells to HIV persistence during ART.

Short Communication: Few Liver-Infiltrating Cells Express CXCR3 in HIV/HCV Patients Commencing Antiretroviral Therapy.

Coinfections with Hepatitis C virus and human immunodeficiency virus accelerate the progression of both conditions and hamper effective treatment. Here we describe expression of CXCR3 on liver-infiltrating cells and peripheral T cells from coinfected patients commencing antiretroviral therapy (ART) in Indonesia. CXCR3 was expressed by small number of intrahepatic inflammatory cells, mostly in the portal areas. The number of cells did not change on ART and was markedly lower than the number of CD4+ and CD8+ cells in the liver. Data suggest that CXCR3 may contribute to liver infiltration but demonstrate a dynamic situation, changing as the immune system recovers on ART.

Circulating T helper and T regulatory subsets in untreated early rheumatoid arthritis and healthy control subjects.

The pathogenic role and frequency of T cell subtypes in early rheumatoid arthritis are still unclear. We therefore performed a comprehensive analysis of the circulating T cell subtype pattern in patients with untreated early rheumatoid arthritis compared to healthy control subjects. Peripheral blood mononuclear cells were obtained from 26 patients with untreated early rheumatoid arthritis and from with 18 age- and sex-matched healthy control subjects. T helper cell types Th0, Th1, Th2, Th17, and Th1/17 and nonclassic T helper subsets were defined by flow cytometry based on the expression of chemokine receptors CCR4, CCR6, and CXCR3. Regulatory T cells were defined by expression of CD25+ CD127low and also FOXP3 CXCR5+ cells among regulatory and nonregulatory T cells were defined as T follicular regulatory and T follicular helper cells, respectively. The phenotype of T cell subsets was confirmed by transcription factor and cytokine secretion analyses. Multivariate discriminant analysis showed that patients with untreated early rheumatoid arthritis were segregated from healthy control subjects based on the circulating T cell subset profile. Among the discriminator subsets, CCR4+CXCR3- (Th2 and Th17), CTLA4+ and FOXP3+ subsets were present in significantly higher frequencies, whereas CCR4- (Th1/Th17, CCR6+CCR4-CXCR3-, and Th1) subsets were present in lower frequencies in patients with untreated early rheumatoid arthritis compared with healthy control subjects. The proportions of Th2 and Th17 subsets associated positively with each other and negatively with the CXCR3+/interferon γ-secreting subsets (Th1 and Th1/Th17) in patients with untreated rheumatoid arthritis. The proportions of Th2 cells increased with age in patients with untreated early rheumatoid arthritis and healthy control subjects. The dominance of circulating CCR4+CXCR3- T helper subsets (Th2 and Th17) in untreated early rheumatoid arthritis point toward a pathogenic role of these cells in early stages of the disease.

Increased CD56(bright) NK cells in HIV-HCV co-infection and HCV mono-infection are associated with distinctive alterations of their phenotype.

BACKGROUND: HIV-HCV co-infection is associated with accelerated progression to hepatic fibrosis, cirrhosis and hepatocellular carcinoma than HCV mono-infection. The contribution of innate immunity during HIV-HCV co-infection has been a relatively under-investigated area. Natural killer (NK) cells are pivotal sentinels of innate immunity against viruses and tumour cells. In this study we evaluated the effect of HIV-HCV co-infection on peripheral blood NK cell subsets with emphasis on the phenotype of CD56(bright) NK cells. METHODS: Sixty patients were included in the study; HIV mono-infected (n = 12), HCV mono-infected (n = 15), HCV-HIV co-infected (n = 21) and healthy controls (n = 16). PBMCs were isolated and immunophenotyping of NK cells was performed by flowcytometry. RESULTS: We observed an expansion of CD56(bright) NK cell subset in HIV-HCV co-infection as compared to healthy controls and HIV mono-infected group. All the infected groups had an upregulated expression of the activating receptor NKG2D on CD56(bright) NK cells in comparison to healthy controls while not differing amongst themselves. The expression of NKp46 in HIV-HCV co-infected group was significantly upregulated as compared to both HIV as well as HCV mono-infections while NKp30 expression in the HIV-HCV co-infected group significantly differed as compared to HIV mono-infection. The CD56(bright) NK cell subset was activated in HIV-HCV co-infection as assessed by the expression of CD69 as compared to healthy controls but was significantly downregulated in comparison to HIV mono-infection. CD95 expression on CD56(bright) NK cells followed the same pattern where there was an increased expression of CD95 in HIV mono-infection and HIV-HCV co-infection as compared to healthy controls. In contrast to CD69 expression, CD95 expression in HCV mono-infection was decreased when compared to HIV mono-infection and HIV-HCV co-infection. Finally, expression of CXCR3 on CD56(bright) NK cells was increased in HIV-HCV co-infection in comparison to HIV mono-infection while remaining similar to HCV mono-infection. CONCLUSION: Thus, HIV-HCV co-infection is able to modulate the phenotype of CD56(bright) NK cell subset in a unique way such that NKp46 and CXCR3 expressions are distinct for co-infection while both mono-infections have an additive effect on CD56(bright), CD69 with CD95 expressions. HCV mono-infection has a dominant effect on NKp30 expression while NKG2D and CD127 expressions remained same in all the groups.

Direct evidence for activated CD8+ T cell transmigration across portal vein endothelial cells in liver graft rejection.

BACKGROUND: Lymphocyte recruitment into the portal tract is crucial not only for homeostatic immune surveillance but also for many liver diseases. However, the exact route of entry for lymphocytes into portal tract is still obscure. We investigated this question using a rat hepatic allograft rejection model. METHODS: A migration route was analyzed by immunohistological methods including a recently developed scanning electron microscopy method. Transmigration-associated molecules such as selectins, integrins, and chemokines and their receptors expressed by hepatic vessels and recruited T-cells were analyzed by immunohistochemistry and flow cytometry. RESULTS: The immunoelectron microscopic analysis clearly showed CD8ß(+) cells passing through the portal vein (PV) endothelia. Furthermore, the migrating pathway seemed to pass through the endothelial cell body. Local vascular cell adhesion molecule-1 (VCAM-1) expression was induced in PV endothelial cells from day 2 after liver transplantation. Although intercellular adhesion molecule-1 (ICAM-1) expression was also upregulated, it was restricted to sinusoidal endothelia. Recipient T-cells in the graft perfusate were CD25(+)CD44(+)ICAM-1(+)CXCR3(+)CCR5(-) and upregulated α4ß1 or αLß2 integrins. Immunohistochemistry showed the expression of CXCL10 in donor MHCII(high) cells in the portal tract as well as endothelial walls of PV. CONCLUSIONS: We show for the first time direct evidence of T-cell transmigration across PV endothelial cells during hepatic allograft rejection. Interactions between VCAM-1 on endothelia and α4ß1 integrin on recipient effector T-cells putatively play critical roles in adhesion and transmigration through endothelia. A chemokine axis of CXCL10 and CXCR3 also may be involved.

Persistence of integrated HIV DNA in CXCR3 + CCR6 + memory CD4+ T cells in HIV-infected individuals on antiretroviral therapy.

BACKGROUND: HIV latent infection can be established in vitro by treating resting CD4 T cells with chemokines that bind to chemokine receptors (CKR), CCR7, CXCR3, and CCR6, highly expressed on T cells. OBJECTIVE: To determine if CKR identify CD4 T cells enriched for HIV in HIV-infected individuals receiving suppressive antiretroviral therapy (ART). DESIGN: A cross-sectional study of CKR expression and HIV persistence in blood from HIV-infected individuals on suppressive ART for more than 3 years (n = 48). A subset of 20 individuals underwent leukapheresis and sorting of specific CD4 T-cell subsets. METHODS: We used flow cytometry to quantify CCR5, CCR6, CXCR3, and CXCR5 expression on CD4 T cells. HIV persistence was quantified using real-time Polymerase Chain Reaction to detect total, integrated HIV DNA, 2-long terminal repeat circles and cell-associated unspliced (CA-US) HIV RNA in total CD4 T cells from blood or sorted T-cell subsets. Associations between CKR and HIV persistence in CD4 T cells in blood were determined using regression models and adjusted for current and nadir CD4 T-cell counts. RESULTS: The frequency of cells harbouring integrated HIV DNA was inversely associated with current CD4 T-cell count and positively associated with CCR5+ CD4 T cells, CXCR3+CCR6+ and CXCR3+CCR6- expression on total memory CD4 T cells (P < 0.001, 0.048, 0.015, and 0.016, respectively). CXCR3+CCR6+ CM CD4 T cells contained the highest amount of integrated HIV DNA and lowest ratio of CA-US HIV RNA to DNA compared to all T-cell subsets examined. CONCLUSION: CXCR3 and CCR6 coexpression defines a subset of CD4 T cells that are preferentially enriched for HIV DNA in HIV-infected individuals on ART.

Epidermotropic B-Cell Lymphoma: A Unique Subset of CXCR3-Positive Marginal Zone Lymphoma.

BACKGROUND: Epidermotropic B-cell lymphoma is a very rare entity that has primarily been reported in the literature as anecdotal case reports. The majority of the reported cases exhibit a diffuse skin rash affecting middle-aged to older adults with a male predominance. The exact mechanism of marginal zone B-cell localization to the epidermis is unclear. MATERIAL AND METHODS: To describe a very rare subset of cutaneous B-cell lymphoma and explore potential pathogenetic mechanisms for the epidermotropic tendency, the hospital database and literature review was conducted to isolate cases of epidermotropic B-cell lymphoma. Routine hematoxylin and eosin stain followed by selective phenotypic studies. RESULTS: Two of the cases were encountered in the hospital database, whereas 5 cases have been previously reported; material was requested on previously reported cases and was received on 3 of them. In one of the 2 cases encountered in our database, the patient presented with a progressive skin rash over 7 months resembling pityriasis rosea. Subsequent to a diagnosis of B-cell lymphoma, further staging revealed bone marrow involvement. The other patient, an elderly female, presented with isolated nodules. The biopsies of both cases showed areas of superficial band-like lymphocytic infiltration with large monocytoid appearance and an epidermotropic pattern of lymphocyte migration into the epidermis. Neoplastic cells were extensively positive for CD20, CD79a, and BCL-2 and negative for CD10 and BCL-6. Of interest, a similar pityriasis rosea-like presentation was encountered in the cases reported in the literature. All patients were elderly males with established bone marrow, peripheral blood, and spleen involvement several months to years after the initial cutaneous presentation in 3 of them. None of the patients to date have died of lymphoma. CXCR3 epidermotropic B cells were detected in both our cases and in 3 of the 3 previously published cases. CONCLUSIONS: Epidermotropic B-cell lymphoma represents a subset of marginal zone lymphoma characterized by a papulosquamous rash most frequently resembling pityriasis rosea, occurring almost exclusively in older males. We speculate that aberrant expression of CXCR3 in marginal zone lymphoma of the skin is associated with migration of lymphoma cells to the epidermis and could lead to an epidermotropic pattern given the known role of CXCR3 expression in neoplastic T cells in the localization of mycosis fungoides to the epidermis. There is a tendency toward bone marrow, spleen, and peripheral blood involvement.

Low expression of activation marker CD69 and chemokine receptors CCR5 and CXCR3 on memory T cells after 2009 H1N1 influenza A antigen stimulation in vitro following H1N1 vaccination of HIV-infected individuals.

Unlike well-studied antibody responses to pandemic 2009 H1N1 influenza A virus vaccines in human immunodeficiency virus-infected (HIV+) individuals, less well understood are cell-mediated immune (CMI) responses to this antigen in this susceptible population. We investigated such influenza-specific CMI responses in 61 HIV+ individuals and in 20 HIV-negative (HIV-) healthy controls. Each was vaccinated with a single licensed dose of inactivated, split-virion vaccine comprised of the influenza A/California/7/2009 (H1N1) virus-like strain. Cells collected just prior to vaccination and at 1 and 3 months afterwards were stimulated in vitro with dialyzed vaccine antigen and assayed by flow cytometry for cytokines TNF-α, IFN-γ, IL-2, and IL-10, for degranulation marker CD107a, as well as phenotypes of memory T-cell subpopulations. Comparable increases of cytokine-producing and CD107a-expressing T cells were observed in both HIV+ subjects and healthy HIV-controls. However, by 3 months post-vaccination, in vitro antigen stimulation of peripheral blood mononuclear cells induced greater expansion in controls of both CD4 and CD8 central memory and effector memory T cells, as well as higher expression of the activation marker CD69 and chemokine receptors CCR5 and CXCR3 than in HIV+ subjects. We concluded CD4+ and CD8+ memory T cells produce cytokines at comparable levels in both groups, whereas the expression after in vitro stimulation of molecules critical for cell migration to infection sites are lower in the HIV+ than in comparable controls. Further immunization strategies against influenza are needed to improve the CMI responses in people living with HIV.

The CXCR3-CXCL11 signaling axis mediates macrophage recruitment and dissemination of mycobacterial infection.

The recruitment of leukocytes to infectious foci depends strongly on the local release of chemoattractant mediators. The human CXC chemokine receptor 3 (CXCR3) is an important node in the chemokine signaling network and is expressed by multiple leukocyte lineages, including T cells and macrophages. The ligands of this receptor originate from an ancestral CXCL11 gene in early vertebrates. Here, we used the optically accessible zebrafish embryo model to explore the function of the CXCR3-CXCL11 axis in macrophage recruitment and show that disruption of this axis increases the resistance to mycobacterial infection. In a mutant of the zebrafish ortholog of CXCR3 (cxcr3.2), macrophage chemotaxis to bacterial infections was attenuated, although migration to infection-independent stimuli was unaffected. Additionally, attenuation of macrophage recruitment to infection could be mimicked by treatment with NBI74330, a high-affinity antagonist of CXCR3. We identified two infection-inducible CXCL11-like chemokines as the functional ligands of Cxcr3.2, showing that the recombinant proteins exerted a Cxcr3.2-dependent chemoattraction when locally administrated in vivo. During infection of zebrafish embryos with Mycobacterium marinum, a well-established model for tuberculosis, we found that Cxcr3.2 deficiency limited the macrophage-mediated dissemination of mycobacteria. Furthermore, the loss of Cxcr3.2 function attenuated the formation of granulomatous lesions, the typical histopathological features of tuberculosis, and led to a reduction in the total bacterial burden. Prevention of mycobacterial dissemination by targeting the CXCR3 pathway, therefore, might represent a host-directed therapeutic strategy for treatment of tuberculosis. The demonstration of a conserved CXCR3-CXCL11 signaling axis in zebrafish extends the translational applicability of this model for studying diseases involving the innate immune system.

Compartmentalization of innate immune responses in the central nervous system during cryptococcal meningitis/HIV coinfection.

OBJECTIVE: The role of innate immunity in the pathogenesis of cryptococcal meningitis is unclear. We hypothesized that natural killer (NK) cell and monocyte responses show central nervous system (CNS) compartment-specific profiles, and are altered by antifungal therapy and combination antiretroviral therapy (cART) during cryptococcal meningitis/HIV coinfection. DESIGN: Substudy of a prospective cohort study of adults with cryptococcal meningitis/HIV coinfection in Durban, South Africa. METHODS: We used multiparametric flow cytometry to study compartmentalization of subsets, CD69 (a marker of activation), CXCR3 and CX3CR1 expression, and cytokine secretion of NK cells and monocytes in freshly collected blood and cerebrospinal fluid (CSF) at diagnosis (n = 23), completion of antifungal therapy induction (n = 19), and after a further 4 weeks of cART (n = 9). RESULTS: Relative to blood, CSF was enriched with CD56(bright) (immunoregulatory) NK cells (P = 0.0004). At enrolment, CXCR3 expression was more frequent among blood CD56(bright) than either blood CD56(dim) (P < 0.0001) or CSF CD56(bright) (P = 0.0002) NK cells. Antifungal therapy diminished blood (P < 0.05), but not CSF CXCR3(pos) NK-cell proportions nor CX3CR1(pos) NK-cell proportions. CD56(bright) and CD56(dim) NK cells were more activated in CSF than blood (P < 0.0001). Antifungal therapy induction reduced CD56(dim) NK-cell activation in CSF (P = 0.02). Activation of blood CD56(bright) and CD56(dim) NK cells was diminished following cART commencement (P < 0.0001, P = 0.03). Immunoregulatory NK cells in CSF tended to secrete higher levels of CXCL10 (P = 0.06) and lower levels of tumor necrosis factor α (P = 0.06) than blood immunoregulatory NK cells. CSF was enriched with nonclassical monocytes (P = 0.001), but antifungal therapy restored proportions of classical monocytes (P = 0.007). CONCLUSION: These results highlight CNS activation, trafficking, and function of NK cells and monocytes in cryptococcal meningitis/HIV and implicate immunoregulatory NK cells and proinflammatory monocytes as potential modulators of cryptococcal meningitis pathogenesis during HIV coinfection.