Angiocentric lymphoma with granulomatous panniculitis in the skin expressing natural killer cell and large granular T-cell phenotypes

We investigated three patients suffering from angiocentric lymphoma with granulomatous panniculitis in the skin. All three patients presented with multiple purple subcutaneous nodules. Immunohistologically, the lymphoma cells in all three patients expressed CD2 (T-11), CD56 (neural cell adhesion molecule), and Mik-1 (interleukin-2 receptor). CD3s (CD3, Leu-4)-positive lymphoma cells were found in two patients. A pore-forming protein (perforin) was detected in the lymphoma cells of all three patients. Perforin-possessing lymphoid cells were focally scattered in 2 of 15 patients with CD56-negative cutaneous lymphomas who served as controls. By the Southern blot method, one patient showed a rearranged T-cell receptor (TcR) gene in the biopsied specimen, and the other two patients had germline configurations of TcRs and immunoglobulin heavy chain genes. One patient had serum anti-human T-cell lymphotropic virus (HTLV)-I antibody, but showed no integration of its proviral DNA. Ultrastructurally, membrane-bound azurophilic granules were detected in the atypical lymphoid cells of all three patients. Angiocentric lymphoma with panniculitis in three patients showed the characteristics of natural killer and large granular T-cells. The histological features might be due to the characteristics of the neoplastic cells with azurophilic granules and perforin.This work was supported in part by Grants in Aid from the Fukuoka Cancer Society, Japan     

Control of self-reactive cytotoxic T lymphocytes expressing γδ T cell receptors by natural killer inhibitory receptors

The majority of peripheral blood γδ T cells in human adults expresses T cell receptors (TCR) with identical V regions (Vγ9 and Vδ2). These Vγ9Vδ2 T cells recognize the major histocompatibility complex (MHC) class I-deficient B cell line Daudi and broadly distributed nonpeptidic antigens present in bacteria and parasites. Here we show that unlike αβ or Vγ9^? γδ T cells, the majority of Vγ9Vδ2T cells harbor natural killer inhibitory receptors (KIR) (mainly CD94/NKG2A heterodimers), which are known to deliver inhibitory signals upon interaction with MHC class I molecules. Within Vγ9δ2 T cells, KIR were mainly expressed by clones exhibiting a strong lytic activity against Daudi cells. In stark contrast, almost all Vγ9Vδ2 T cell clones devoid of killing activity were KIR^?, thus suggesting a coordinate acquisition of KIR and cytotoxic activity within Vγ9Vδ2 T cells. In functional terms, KIR inhibited lysis of MHC class I-positive tumor B cell lines by Vγ9Vδ2 cytotoxic T lymphocytes (CTL) and raised their threshold of activation by microbial antigens presented by MHC class I-positive cells. Furthermore, masking KIR or MHC class I molecules revealed a TCR-dependent recognition by Vγ9Vδ2 CTL of ligands expressed by activated T lymphocytes, including the effector cells themselves. Taken together, these results suggest a general implication of Vγ9Vδ2 T cells in immune response regulation and a central role of KIR in the control of self-reactive γδ CTL.     

Association of a 70-kDa tyrosine phosphoprotein with the CD16:ζ:γ complex expressed in human natural killer cells

The CD16: ζ: γ receptor complex allows natural killer (NK) cells to recognize and eliminate antibody-coated target cells. Whereas the ectodomain of CD16 is the receptor for Fcγ domains of immunoglobulins, disulfide-linked homo- and heterodimers composed of ζ and γ are required for the cell surface expression, and signal transduction properties of the complex. Engagement of CD16 activates the tyrosine kinase pathway, which induces the tyrosine phosphorylation of several substrates, including the ζ subunit and the phospholipase C γ-1 and γ-2 isoforms. Here we show that CD 16 stimulation of either peripheral blood NK cells, leukemic NK cells, or Jurkat transformants expressing a CD16:ζ:γ receptor complex, results in the tyrosine phosphorylation of a 70 kDa ζ-associated protein (pp70). Similarly, a 70-kDa ζ-associated phosphoprotein in T cells has been shown to be a tyrosine kinase (ZAP-70). Peptide mapping analysis indicates that the 70-kDa ζ-associated phosphoproteins from T cells and NK cells are structurally indistinguishable. We conclude that the CD16:ζ:γ complex may use a ZAP-70-related non-receptor tyrosine kinase, in the CD16 signaling cascade leading to NK cell activation.     

Frequent occurrence of in vivo clonal expansion of CD4− CD8− T cells bearing T cell receptor αβ chains in adult humans

We have previously reported 2 cases of healthy men showing in vivo monoclonal expansion of mature CD4^? CD8^? αβ T cells. In the present study, an additional 3 adults were found to exhibit such an expansion, among a total 464 adult donors studied. These 5 individuals were otherwise physiologically normal, with no history of severe illness and autoimmune disease at the time of examination. To investigate the mechanisms of the clonal expansion, further characterization of the clonal cells was attempted. No apparent preference for usage of the Tcell receptor β chain variable region was observed in the clonal T cells. These clonal T cells showed lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities, whereas they could not lyse autologous lymphoblastoid cell lines. Failure of Fas antigen expression was not observed for any of these clones. These results suggest that clonal expansion of CD4^? CD8^? αβ T cells frequently occurs in the periphery without any T cell abnormalities.     

SHORT COMMUNICATION: CD3− CD56+ CD16+ Natural Killer Cells and Improvement of Pregnancy Outcome in IVF/ICSI Failure After Additional IVIG‐Treatment

Citation Heilmann L, Schorsch M, Hahn T. CD3^? CD56⁺ CD16⁺ Natural killer cells and improvement of pregnancy outcome in IVF/ICSI failure after additional IVIG‐treatment. Am J Reprod Immunol 2010; 63: 263–265 Problem The purpose of this retrospective, observational study was to investigate whether additional treatment with intravenous immunglobulin (IVIG) increased the rate of successful pregnancies after repeated implantation failure (RIF). The retrospective data were compared with data of patients without IVIG‐therapy from the meta‐analysis of Clark et al. Method of study A total of 188 women with 226 treatment cycles between 2007 and 2009 were evaluated for IVIG therapy. The percentage of NK cells was measured two times before a new embryo transfer (only women with NK cell percentages >12% were included) and after embryo transfer at a positive pregnancy test. Results In comparison with the meta‐analysis of Clark et al., we observed a pregnancy rate of 50.5%, an implantation rate of 21% and a miscarriage rate of 16.8%. In 42%/IVIG‐ patient or 34.9%/embryo transfer, we observed a live born baby. The live born rate per embryo was 16.6%. In accordance with the study of Kwak et al., we indicate a decrease in the NK cells in patients with improved pregnancy outcome. Conclusion In a subgroup of RIF‐patients with high level of CD56⁺ CD16⁺ NK‐cells the additional application of IVIG leads to a favourable pregnancy outcome.     

Inhibition of R5‐tropic HIV type‐1 replication in CD4+ natural killer T cells by γδ T lymphocytes

After the development of highly active anti‐retroviral therapy, it became clear that the majority of emergent HIV‐1 is macrophage‐tropic and infects CD4⁺, CCR5‐expressing cells (R5‐tropic). There are three distinct cell populations, R5‐tropic, HIV‐1‐susceptible CD4⁺ cells: (i) natural killer T (NKT) cells, (ii) dendritic cells and macrophages, and (iii) tissue‐associated T cells residing primarily at mucosal surfaces. We have confirmed that CD4⁺ NKT cells derived from peripheral blood mononuclear cells (PBMCs) predominantly express CCR5 rather than CXCR4, whereas the reverse is true for CD4⁺ T cells derived from circulating PBMCs, and that R5‐tropic HIV‐1 expands efficiently in the CD4⁺ NKT cells. Moreover, when PBMCs depleted of CD8α⁺ cells were stimulated in the presence of α‐galactosylceramide (α‐GalCer) and R5‐tropic HIV‐1 [NL(AD8)], the production of HIV‐1 virions was not suppressed, whereas, similar to the untreated PBMCs, depletion of CD8β⁺ cells from PBMCs significantly inhibited virion production. These findings suggest that CD8αα⁺ but not CD8αβ⁺ cells may have the ability to inhibit R5‐tropic HIV‐1 replication in CD4⁺ NKT cells. Here, we show that co‐culturing R5‐tropic HIV‐1‐infected CD4⁺ NKT cells with CD8αα⁺ γδ T cells, in particular Vγ1Vδ1 cells, but not with CD8αα⁺ NKT cells or CD8αα⁺ dendritic cells, inhibits HIV‐1 replication mainly by secreting chemokines, such as macrophage inflammatory proteins 1α and 1β and RANTES. Collectively, these results indicate the importance of CD8αα⁺ γδ T cells in the control of R5‐tropic HIV‐1 replication and persistence in CD4⁺ NKT cells.     

Natural killer cell receptor expression reflects the role of human cytomegalovirus in the pathogenesis of a subset of CD4+ T-cell large granular lymphocytosis

A high frequency of CD4(+) T-cell large granular lymphocyte (T-LGL) lymphocytosis occurs in human leukocyte antigen (HLA) -DRB1*0701 individuals displaying monoclonal expansions of Vβ13.1+ CD4(+) T-cell clones, which specifically respond to human cytomegalovirus (HCMV) antigens. We previously reported the expression of natural killer (NK)-cell associated receptors (NKR) by HCMV-specific cytolytic CD4(+) T cells from healthy donors. In the present study a high expression of different NKR (i.e., NKG2D, killer Ig-like receptors (KIR), CD94, ILT2) was observed in CD4(+) T cells from both Vβ13.1- and Vβ13.1+ CD4(+) T-LGL cases. Remarkably, elevated numbers of CD94/NKG2C+ NK cells, previously shown to expand in association to HCMV infection, were preferentially found in Vβ13.1+ T-LGL, further supporting its role in the pathogenesis of a subset of CD4(+) T-LGL.     

Induction of natural killer cell migration by monocyte chemotactic protein−1, −2 and −3

Under certain physiological and pathological conditions, naturall killer (NK) cells rapidly accumulate in tissues. Chemokines are an essential component of the current paradigm of leukocyte recruitment. The present study was designed to investigate the responsiveness of NK cells to the prototypic C-C chemokine, monocyte chemotactic protein-1 (MCP-1). MCP-1 induced migration across filters of interleukin (IL)-2-activated NK cells, whereas it was a weak attractant for unstimulated cells. Maximal induction of migration required a positive concentration gradient between the lower and the upper compartment of the chemotaxis chamber. Preliminary characterization of the MCP-1 receptor on NK cells indicated that the chemotactic response to MCP-1 was blocked by pre-treatment of cells with Bordetella pertussis toxin, and MCP-1 but not IL-8 displaced ¹²⁵I-labeled MCP-1 from IL-2-activated NK cells. The related chemokines MCP-2 and MCP-3 were also active – though less potent – attractants for activated NK cells. Thus the spectrum of action of MCP-1, -2 and -3 encompasses NK cells and chemokines are likely to play a role in regulating extravasation of these cells.     

Expression of an avian CD6 candidate is restricted to αβ T cells,splenic CD8+ γδ T cells and embryonic natural killer cells

A candidate avian CD6 homolog is identified by the S3 monoclonal antibody. The S3 antigen exists in a phosphorylated glycoprotein form of 130 kDa and a nonphosphorylated form of 110 kDa. Removal of phosphate groups and N-linked carbohydrates indicates a 78-kDa protein core. During thymocyte differentiation, the γδ T cells do not express S3, whereas mature CD4⁺ and CD8⁺ cells of αβ lineage acquire S3 antigen. All αβ T cells in the blood and spleen express the S3 antigen at relatively high levels. In contrast, only the CD8⁺ sub-population of γδ T cells in the spleen expresses the antigen and neither αβ nor γδ T cells in the intestinal epithelium express the S3 antigen. The S3 antigen is also found on embryonic splenocytes with a phenotypic profile characteristic of avian natural killer cells. The biochemical characteristics and this cellular expression pattern imply that the S3 antigen is the chicken CD6 homolog.     

Thymus-derived cytokine(s) including interleukin-7 induce increase of T cell receptor α/β+ CD4−CD8− T cells which are extrathymically differentiated in athymic nude mice

Extrathymic T cell differentiation pathways have been reported, although the thymus is the main site of T cell differentiation. The thymus is also known to produce several cytokines that induce proliferation of thymocytes. In the present study, we investigated the influence of thymus-derived cytokines on extrathymic T cell differentiation by intraperitoneal implantation with a diffusion chamber which encloses fetal thymus (we named it fetal thymus-enclosed diffusion chamber, FTEDC) in athymic BALB/c nu/nu mice. Increase in number of T cells bearing T cell receptor (TcR) α/β was detected in lymph nodes and spleens of FTEDC-implanted nude mice 1 week after implantation, whereas no such increase was detected in control nude mice implanted with a diffusion chamber without thymus. The FTEDC-induced increase of T cells was suppressed by intraperitoneal injection of anti-interleukin-7 monoclonal antibody (mAb). The TcR α/β T cells in FTEDC-inplanted BALB/c nu/nu mice preferentially expressed Vβ11, although Vβ11-positive T cells are deleted in the thymus of euthymic BALB/c mice by clonal elimination of self-superantigen Dvb 11-specific T cells. TcR α/β T cells in FTEDC-implanted nude mice were of CD4^?CD8^? phenotype and showed no proliferative response against anti-TcR monoclonal antibody stimulation. These results suggest that the thymus can induce extrathymic T cell differentiation through the influence of thymus-derived cytokine(s) including interleukin-7, and that such extrathymically differentiated T cells have acquired only a little or no ability for proliferation when they recognize antigen by their TcR.     

Encephalitogenic,myelin basic protein-specific T cells from naive rat thymus: preferential use of the T cell receptor gene Vβ8.2 and expression of the CD4− CD8− phenotype

Using a primary limiting dilution approach to generate T cell lines, we compared myelin basic protein (MBP)-specific T cell clones from naive unprimed Lewis rat thymuses with the corresponding T cell repertoire of primed rats. We found that in the naive thymus repertoire MBP-specific, encephalitogenic T cell clones preferentially use T cell receptor Vβ8.2 genes, along with CDR3 sequences typical for the primed Lewis anti-MBP response. In contrast to T cells from primed immune organs, which all display the CD4⁺ CD8^? phenotype, the majority of naive thymus-derived T cell clones expressed reduced levels of the CD4 co-receptor. Some clones were completely CD4^?CD8^?, while others included CD4^? CD8^? subpopulations along with CD4⁺CD8^? T cells. In the one mixed population examined in detail, the CD4^?CD8^? and CD4⁺CD8^? T cell subpopulations used a T cell receptor with identical β chain sequence. The data suggest that in the Lewis rat the biased T cell receptor gene usage by encephalitogenic T cells is a property of the natural thymic T cell repertoire, possibly as a consequence of positive selection. The unusually low expression of CD4 in the major histocompatibility complex class II-restricted autoreactive T cells could be related to their escape from negative selection within the thymus.     

Establishment of Tac-negative,interleukin-2-dependent cytotoxic cell lines from large granular lymphocytes (LGL) of patients with expanded LGL populations

Cell lines were established from purified large granular lymphocites (LGL) isolated from the peripheral blood of seven patients with phenotypically homogeneous LGL expansions. LGL were stimulated with phytohemagglutinin (PHA) or recombinant interleukin-2 (rIL-2) and further expandedin vitro in IL-2-containing media. The surface phenotype of LGL, as assessed by monoclonal antibody staining, was T3⁺ T8⁺ in five patients, T3^– T8^– in one, and T3⁺ T8^– in another patient. The cells also expressed Leu 7, Leu 11, and/or OKM 1 markers in various proportions and were identifiable as LGL by their morphological and cytochemical features. The original surface phenotype of the unstimulated LGL was retained in the IL-2-dependent cell lines from each individual patient, i.e., T3⁺ T8⁺ cells originated T3⁺ T8⁺ cell lines and T3^– T8^– cells originated T3^– T8^– cell lines. Other markers, such as Leu 11 and OKM 1, were generally lost in culture. LGL proliferated in response to rIL-2 but did not express detectable IL-2 receptors, even after prolonged periods of culture. All cell lines from each individual patient had the same surface phenotype, and within the single lines, all of the cells expressed the same markers. Cell lines from two patients consistently displayed chromosomal abnormalities. Although different in the two patients, the abnormalities were identical in all of the lines from the same patient and detectable in most of the cells examined, suggesting a clonal origin for the abnormally expanded LGL populations. Freshly isolated LGL did not exert NK activity. However, the IL-2-dependent LGL lines acquired the ability to kill K562 target cells and to produce gamma interferon (-IFN). No direct correlation was observed between these two properties.     

The human natural killer cell receptor for major histocompatibility complex class I molecules. Surface modulation of p58 molecules and their linkage to CD3 ζ chain,FcϵRI γ chain and the p56lck kinase

The natural killer cell (NK)-specific p58 surface molecules, recognized by the GL183 and EB6 monoclonal antibodies (mAb), have been shown to represent the putative NK receptor for HLA-C molecules. The interaction between p58 receptors and HLA-C results in inhibition of the NK-mediated target cell lysis. In this study, GL183^?EB6⁺ clones (Cw4-specific), after mAb-induced surface modulation of EB6 molecules, acquired the ability to lyse the Cw4^? C1R cells. In NK clones co-expressing both GL183 and EB6 molecules and unable to kill Cw3-protected target cells, the mAb-induced modulation of EB6 molecules resulted both in selective co-modulation of GL183 molecules and in the lysis of Cw3-transfected P815 murine cells. In line with the co-modulation experiments we also show that the GL183 and EB6 molecules can be co-immunoprecipitated from GL183⁺/EB6⁺ clones after cell lysis in the presence of digitonin. The p58 receptor also revealed an association with molecules belonging to the ζ family (i.e. CD3 ζ and Fc?RI γ chains). Two-dimensional diagonal gel analysis of the p58 complex immunoprecipitated from polyclonally activated p58⁺ NK cells indicated a preferential association with CD3 ζ chains either in the form of covalently linked ζ-γ homodimers or in the form of ζ-γ heterodimers, while γ-γ homodimers were detectable in low amounts. However, p58⁺ clones displaying a unique association with γ-γ homodimers could also be isolated. Probing the immunoprecipitated p58 complex with anti-p56^lck antibody also revealed an association with this member of the src family. In addition, mAb-mediated signaling of NK clones via p58 molecules induced increments of p58/p56^lck association. However, under the same experimental conditions that induced optimal in vivo tyrosine phosphorylation of the CD16-associated CD3 ζ chains, no tyrosine phosphorylation was detected in the p58-associated CD3 ζ, chains. In these in vivo experiments neither anti-CD16 nor anti-p58 mAb could induce tyrosine phosphorylation of the γ chains. Finally, the anti-p58-mediated inhibition of the NK cell triggering via CD16 molecules was not accompained by a down-regulation of the tyrosine phosphorylation of the CD16-associated CD3 ζ chains.     

Expansion of the CD4−, CD8− γδ T cell subset in the spleens of mice during non-lethal blood-stage malaria

Splenic γδ T cells (CD4^?, CD8^?) increased more that 10-fold upon resolution of either Plasmodium chabaudi adami or P. c. chabaudi infections in C57BL/6 mice compared to controls. Similarly, a 10- to 20-fold expansion of the γδ T cell population was observed in β₂-microglobulin deficient (β²-m^0.0) mice that had resolved P. c. adami, P. c. chabaudi or P. yoelii yoelii infections. In contrast, increases in the number of splenic αβ T cells in these infected mice were only two to three-fold indicating a differential expansion of the γδ T cell subset during malaria. Because nucleated cells of β₂-m^0/0 mice lack surface expression of major histocompatibility complex class I and class Ib glycoproteins, our findings suggest that antigen presentation by these glycoproteins is not necessary for the increasing number of γδ T cells. Our observation that after resolution of P. c. adami malaria, C57BL/6 mice depleted of CD8⁺ cells by monoclonal antibody treatment had lower numbers of γδ T. cells than untreated controls suggests that the demonstrated lack of CD8⁺ cells in β₂-m^0/0 mice does not contribute to the expansion of the γδ T cell population during non-lethal malaria.     

Immunocytochemical characterization of large granular lymphocytes in normal cervix and HPV associated disease.

A quantitative immunocytochemical study of large granular lymphocytes (LGLs) in the normal cervix and in human papillomavirus (HPV) associated disease was performed using a panel of monoclonal antibodies which included those for LGL surface markers CD56, CD16, and CD57. Only CD56-positive cells were found within the ectocervical epithelium and these cells increased in number in cervical intraepithelial neoplasia (CIN) in comparison with normal cervix. Examination of serial sections and double labelling suggests that these cells are CD3+, CD8+, CD56+, CD16+. The observed increase in number of this subset was not associated specifically with HPV infection but was related to CIN. Lymphocytes expressing all three LGL markers were found in the stroma and CD16(+)-positive cells clustered around endocervical glands with occasional cells extending into the endocervical epithelium. These results indicate that a small subset of LGLs which express T-cell markers is increased in number in CIN. Cells expressing classical NK markers are restricted to the stroma and are not found within the ectocervical epithelium.     

Progenies of fetal thymocytes are the major source of CD4−CD8+ αα intestinal intraepithelial lymphocytes early in ontogeny

Present literature supports the view of an extrathymic origin for the subset of intestinal intraepithelial lymphocytes (IEL) that express the CD4^?CD8⁺ αα phenotype. This subset would include virtually all T cell receptor (TCR) γδ IEL and a portion of TCR αβ IEL. However, these reports do not exclude the possibility that some CD4^?CD8⁺ αα IEL are actually thymically derived. To clarify this issue, we examined the IEL day 3 neonatally thymectomized (NTX) mice. NTX resulted in as much as 80 % reduction in total TCR γδ IEL and in a nearly complete elimination of TCR αβ CD4^?CD8⁺ αα IEL early in ontogeny (3-to 5-week-old mice). The thymus dependency of TCR γδ IEL and TCR αβ CD4^?CD8⁺ IEL was less prominent in older mice (7- to 10-week-old mice), as the total number of these IEL increased in NTX mice, but still remained severalfold less than that in euthymic mice. Furthermore, we demonstrate, by grafting the fetal thymus of CBF1 (H-2^b/d) mice under the kidney capsule of congenitally nude athymic mice of BALB/c background (H-2^d), that a substantial number of TCR γδ IEL and TCR αβ CD4^?CD8⁺ αα IEL can be thymically derived (H-2^b+). In contrast, but consistent with our NTX data, grafting of adult thymi into nude mice generated virtually no TCR γδ IEL and relatively less TCR αβ CD4^?CD8⁺ αα IEL than did the grafting of fetal thymi. These results suggest that the thymus is the major source of TCR γδ and TCR αβ CD4^?CD8⁺ αα IEL early in ontogeny, but that the extrathymic pathway is probably the major source of these IEL later in ontogeny. A reassessment of the theory that most CD4^?CD8⁺ IEL are extrathymically derived is needed.