Expression Of HLA-DQ Antigens Research Articles

Pattern of Expression of HLA-DR and HLA-DQ Antigens and mRNA in Myeloid Differentiation

We examined the expression of HLA-DR and HLA-DQ antigens and mRNA from myeloid and lymphoid cells obtained from normal volunteers and established cell lines. Cytofluorometric analysis and immunoprecipitation were performed using murine monoclonal antibodies specific for HLA-DR (L-243) and HLA-DQ (Leu 10). The expression of mRNA for HLA-DR and HLA-DQ chains was determined by Northern blot and RNA dot-blot analysis. Lymphoid cell lines expressed both HLA-DR and HLA-DQ antigens, with consistently higher levels of expression of DR. Myeloid cell lines of early myeloblast or bipotent (myeloid-erythroid) phenotype (KG-1, KG-1a, HEL) expressed HLA-DR at high levels, whereas cell lines manifesting a greater degree of myeloid maturation (ML-3, HL-60, U937) expressed DR at low or undetectable levels. The HLA-DQ antigen was expressed at low levels on the surface of KG-1 and KG-1a cells but was not detectable on other myeloid cell lines. The expression of mRNA for HLA-DR and HLA-DQ chains paralleled the pattern of expression of the respective antigens. The HL-60 and U-937 cells stimulated to differentiate in vitro to macrophages with 1,25 dihydroxyvitamin D3 [1,25(OH)2D3] were induced to express detectable levels of HLA-DR antigens. Exposure to gamma-interferon (gamma-IFN) increased the expression of HLA-DR antigens by all myeloid cell lines. Induction of differentiation in vitro with either 1,25(OH)2D3 or dimethyl sulfoxide potentiated this effect of gamma-IFN. Expression of the HLA-DQ antigens was increased on KG-1 myeloblasts after exposure to gamma-IFN. HLA-DQ expression could not be detected on other myeloid cell lines after exposure to gamma-IFN, nor was HLA-DQ expression stimulated by gamma-IFN after HL-60 and U-937 cells were induced to differentiate to macrophagelike cells in vitro. These results provide additional evidence that expression of the HLA-DR and HLA-DQ genes may be independently regulated in human myeloid cells.

Remarkable correlation between increased HLA-DQ antigen positive monocytes and prognosis of renal transplantation.

Since cyclosporin A (CsA), a widely used immunosuppressive drug, strongly suppresses interleukin-2 (IL-2) secretion, it is frequently difficult to estimate T lymphocyte activation in early acute rejection. We found that, when evaluated based on HLA-DQ antigen expression, monocyte activation in the peripheral blood of renal transplantation patients was a very sharp parameter in diagosing acute rejection. All of 16 episodes of early acute rejection, which were relatively easily suppressed by steroid pulse therapy, showed a sharp increase in the proportion of HLA-DQ antigen-positive monocytes (DQ+ mono) and a quick return of DQ+ mono to previous values, along with a fall in serum creatinine levels. Since, however, HLA-DR antigen-positive T lymphocytes (DR+ T) were markedly increased over a long period in episodes of therapy-resistant and chronic rejection, their prolonged high value was regarded as a parameter indicative of poor prognosis.

Expression of HLA-DQ Antigens in the Small Intestinal Mucosa of Patients with Coeliac Disease

Studies at the DNA and product level of B-cell lines of coeliac patients have shown a strong association between coeliac disease and the HLA-DQ alpha 2.3 and HLA-DQ beta 2.7 alleles. The monoclonal antisera SFR20-DQ alpha 5 and XIII-358.4, which specifically react with HLA-DQ alpha 2.3 and with HLA-DQ beta 2.3 and -DQ beta 2.7, respectively, have been used to detect the expression of these specificities in the small-intestinal mucosa of 7 coeliac patients and 11 non-coeliac persons. An immunoperoxidase technique on frozen tissue sections of jejunal biopsy specimens was used. Positive specimens showed immunoperoxidase staining of lymphocytes and histiocytes in the lamina propria. The epithelial cells showed no immunoperoxidase staining. Positive results at the intestinal level correlated with the HLA typing of the patients and controls. The distribution found for the HLA-DQ alleles in the intestinal mucosa makes the role of a HLA-DQ alpha/beta dimer as gliadin receptor at the epithelial cell less probable, but it is compatible with the hypothesis that these DQ molecules are involved in the regulation of the intestinal immune response to gluten.

Langerhans cells expressing HLA-DQ, HLA-DR and T6 antigens in normal oral mucosa and lichen planus.

We compared Langerhans cells (LC) expressing HLA-DQ, HLA-DR and T6 antigens in biopsies from the same oral mucosal site in 12 patients with oral lichen planus and eight healthy volunteers. LC expressing each antigen were observed in all the specimens, but in lichen planus the cells were located in higher levels of the epithelium than in controls. Compared with controls, lichen planus contained significantly more HLA-DQ-positive LC (P = 0.04) and fewer HLA-DR-positive LC (P = 0.05), but there was no such difference in T6-positive LC. In lichen planus specimens, there were significantly more LC expressing HLA-DQ and T6 than HLA-DR (P = 0.0001 and 0.02 respectively); no such differences were found in normal mucosa. Epithelial cells in lichen planus expressed HLA-DR antigen, but not HLA-DQ or T6 antigens. We conclude that in lichen planus there is modulation of HLA-DR and HLA-DQ antigen expression by LC, or differences in the number of LC expressing those antigens.

Differential Expression of HLA-DR, DQ, and DP Antigens in Primary and Metastatic Melanoma

Fifty-five primary and 33 metastatic surgically removed melanoma lesions were stained in indirect immunoperoxidase with anti HLA-DR, DQ, and DP monoclonal antibodies and with the monoclonal antibody CL203.4 to a 96-K melanoma associated antigen (MAA). The latter antigen may represent a marker to monitor susceptibility of melanoma cells to modulation by IFN-gamma, because it is highly susceptible to induction by IFN-gamma. In primary melanomas 44%, 29%, 10%, and 55% of the lesions tested were evidently stained by anti HLA-DR, DQ, DP, and 96-K MAA monoclonal antibodies, respectively. A statistically significant association (P less than 0.01) was demonstrated between the degree of intratumoral lymphocytic infiltrate and the expression of HLA-DR and HLA-DQ antigens. In addition, a high degree of concordance in the reactivity pattern of individual lesions stained for HLA-DR antigens and for the 96-K MAA was found. In metastases 64%, 33%, 47%, and 100% of the lesions tested were evidently stained by anti HLA-DR, DQ, DP, and 96-K MAA monoclonal antibodies, respectively. This study indicates that HLA-DR and HLA-DP antigens are expressed in a higher percentage of metastatic than of primary melanomas and that there is no marked difference in the expression of HLA-DQ antigens between primary and metastatic melanomas. The data suggest that the regulatory mechanisms which control the expression of HLA-DR and DP antigens in primary and metastatic melanoma lesions are different. Locally produced IFN-gamma may play a role in the regulation of HLA Class II antigens in primary melanomas.

HLA-DR and HLA-DQ antigen expression of anagen and telogen hair bulbs in long-standing alopecia areata

HLA-DR and HLA-DQ antigen expression of anagen and telogen hair bulbs in long-standing alopecia areata

HLA-DR and HLA-DQ antigen expression of anagen and telogen hair bulbs in long-standing alopecia areata

HLA-DR and HLA-DQ antigen expression of anagen and telogen hair bulbs in long-standing alopecia areata

Autologous B lymphoblastoid cell lines and long-term cultured T cells as stimulators in the mixed lymphocyte reaction: analysis of the role of HLA class II antigens as stimulatory molecules.

Human activated T cells, long-term cultured in the presence of interleukin 2 (IL 2), were compared with autologous Epstein Barr virus-transformed B lymphoblastoid cell lines for expression of human leukocyte (HLA)-HLA-DR and -DQ antigens and for ability to induce proliferative responses in autologous and allogeneic lymphocytes. Immunofluorescence analysis performed with a panel of monoclonal antibodies (mAb) specific for HLA-DR or -DQ antigens did not reveal any significant difference in the expression of HLA-DR antigens but revealed reduced expression of HLA-DQ antigens on two out of four T cell lines tested. No obvious difference could be detected in the two-dimensional gel electrophoretic profile of HLA-DR and -DQ beta-chains synthesized by the autologous pairs of B and T cell lines. In contrast with previous reports, the IL 2-dependent cell lines consistently induced alloproliferative responses in standard 6-day mixed lymphocyte cultures; however, these responses were severalfold lower than those elicited by the autologous B lymphoid lines. Both anti-HLA-DR and anti-HLA-DQ mAb blocked the proliferative responses induced by the B cell lines but did not affect those generated by the T cell lines, suggesting that the latter cells induce T lymphocyte activation via a mechanism independent of HLA-DR or -DQ antigen expression on their surface. Addition of IL 2 to the mixed cultures with B cell lines as stimulators did not affect the outcome of the proliferative responses but partially or completely reversed the blocking activity of the mAb. In contrast, IL 2 significantly enhanced the alloproliferation induced by the T lymphoblastoid cell lines, and the anti-HLA class II mAb partially antagonized this effect. Taken together, these data suggest that unlike the HLA-DR and -DQ gene products on B cells, those on IL 2-dependent long-term cultured T cells do not play a direct or primary stimulatory role in the mixed lymphocyte reaction; the reduced levels of alloproliferation induced by the T cell lines are, at least in part, due to a defective production of endogenous IL 2 by the responder lymphocytes rather than to a defective expression of IL 2 receptors by the alloproliferative T cell subset; and the anti-HLA class II mAb in these cultures act only at the responder cell level, since they can efficiently block the enhancement of T cell proliferation triggered by exogenous IL 2, but not the proliferative responses induced by T cell lines in standard conditions.

Ontogenic and functional implications of the differential expression of HLA-DQ antigens on leukemic cells

We have examined the HLA class II antigenic profiles on different types of leukemic cells and have attempted to relate these findings to the normal differentiation pathways of the cells from which they have arisen. Monoclonal antibodies reacting with the different HLA class II determinants, HLA-DR, DRw52(MT), and DQ, were used to study the expression of these antigens on Epstein-Barr virus transformed cell lines, chronic lymphocytic leukemic cells, acute lymphoblastic leukemic blasts, acute myeloblastic leukemic blasts, and established leukemic cell lines by indirect immunofluorescence binding and immunoprecipitations. The results showed that whereas the HLA-DR and HLA-DRw52(MT2) antigens are normally expressed on the majority of the cells tested, there is a different expression of the HLA-DQ antigens on acute leukemic blasts, chronic lymphocytic leukemic cells, and leukemic cell lines indicating that the DQ molecules may be differentiation antigens preferentially expressed on mature cells. Furthermore, when the pre-B cell leukemic line NALM 6 was induced to differentiate with phorbol ester (TPA), normal expression of the HLA-DQ antigen was obtained after 5 days of culture. The absence of HLA-DQ antigens from the acute leukemic blasts suggests that these immature cells “froze” in the early stages of cell differentiation. We discuss these findings in relation to the role of these HLA class II antigens in cell differentiation and the immune response.

The Pattern of HLA-DR and HLA-DQ Antigen Expression on Clonable Subpopulations of Human Myeloid Progenitor Cells

Three subpopulations of human myeloid progenitor cells (CFU-GM) can be distinguished by differences in their kinetics of development; the liquid phase pre-CFU-GM, the day 14 CFU-GM, and the day 7 CFU-GM. The relative cell membrane densities of the HLA-DR and HLA-DQ antigens expressed by the three subpopulations was investigated by comparing the amount of antibody required to deplete bone marrow cell preparations of each cell type. Three separate approaches were used--complement (C') cytotoxicity, antiglobulin/C'-cytotoxicity and immune rosette depletion. Similar results were obtained for all three procedures, although the latter two gave a tenfold greater sensitivity over the standard C'-cytotoxicity method. At saturating anti-HLA-DR antibody concentrations, 85% to 95% of cells within the three myeloid subpopulations were found to express HLA-DR antigens. However, the relative amount of HLA-DR expressed by these subpopulations increased from the pre-CFU-GM to the day 7 CFU-GM. The expression of HLA-DQ antigens was considerably lower and could only be detected by using the more sensitive procedures. Only 50% of day 7 and 14 CFU-GM progenitor cells expressed detectable HLA-DQ antigens, whereas a greater proportion (80%) of the pre-CFU-GM were HLA-DQ positive. The pattern of HLA-DQ expression on these clonable precursors was quite distinct and opposite to the cell membrane density of the HLA-DR antigens. Because these three progenitor cell populations are thought to be linked in differentiation sequence, these results provide indirect support for the hypothesis that HLA class II antigens are implicated in regulatory mechanisms during normal myeloid cell differentiation.

The pattern of HLA-DR and HLA-DQ antigen expression on clonable subpopulations of human myeloid progenitor cells

Three subpopulations of human myeloid progenitor cells (CFU-GM) can be distinguished by differences in their kinetics of development; the liquid phase pre-CFU-GM, the day 14 CFU-GM, and the day 7 CFU-GM. The relative cell membrane densities of the HLA-DR and HLA-DQ antigens expressed by the three subpopulations was investigated by comparing the amount of antibody required to deplete bone marrow cell preparations of each cell type. Three separate approaches were used--complement (C') cytotoxicity, antiglobulin/C'-cytotoxicity and immune rosette depletion. Similar results were obtained for all three procedures, although the latter two gave a tenfold greater sensitivity over the standard C'-cytotoxicity method. At saturating anti-HLA-DR antibody concentrations, 85% to 95% of cells within the three myeloid subpopulations were found to express HLA-DR antigens. However, the relative amount of HLA-DR expressed by these subpopulations increased from the pre-CFU-GM to the day 7 CFU-GM. The expression of HLA-DQ antigens was considerably lower and could only be detected by using the more sensitive procedures. Only 50% of day 7 and 14 CFU-GM progenitor cells expressed detectable HLA-DQ antigens, whereas a greater proportion (80%) of the pre-CFU-GM were HLA-DQ positive. The pattern of HLA-DQ expression on these clonable precursors was quite distinct and opposite to the cell membrane density of the HLA-DR antigens. Because these three progenitor cell populations are thought to be linked in differentiation sequence, these results provide indirect support for the hypothesis that HLA class II antigens are implicated in regulatory mechanisms during normal myeloid cell differentiation.

The in vitro regulation of human thyrocyte HLA-DR antigen expression.

The ability of endocrine organs to express human immune response-associated antigens (Ia), such as HLA-DR, is a subject of intense current interest. In this study, the effects of various potential modulators of thyroid follicular cell HLA-DR expression were examined using in vitro cultures. A culture supernatant containing T-cell-derived lymphokines caused DR antigen expression on 13-18% of thyroid cells; more consistent effects were produced by recombinant gamma-interferon, which led to 46-100% of the thyroid cells becoming HLA-DR positive after 3 days in culture. This effect was both time and concentration dependent and occurred in thyroid cells derived from patients with Graves' disease (n = 7) and Hashimoto's thyroiditis (n = 2) as well as from three subjects with no autoimmune thyroid disease. Thyroid cells stained with the monoclonal antibodies 4F2 and 5E9, which recognize cell activation antigens, regardless of whether they were treated with gamma-interferon. The lectin phytohemagglutinin also induced HLA-DR antigen expression (21-91% of cells positive). This response was dependent on T cell contamination of thyroid cell suspensions, since the effect was inhibited by cyclosporin A. HLA-DQ antigen expression, identified by the Leu-10 monoclonal antibody, was also induced on thyroid cells by gamma-interferon and phytohemagglutinin. In contrast, neither recombinant alpha-interferon nor interleukin-2 induced HLA-DR antigens. Irradiation reduced the response of thyroid cells to gamma-interferon, but two of the known inhibitors of macrophage Ia expression, prostaglandin E2 and (Bu)2cAMP, did not affect gamma-interferon-induced thyroid cell HLA-DR expression. We were unable to detect interleukin-1 production by thyroid cells. These results suggest that 1) under normal circumstances, thyroid cells are 4F2 and 5E9 positive, but are incapable of expressing Ia antigens and, thus, of activating T cells to initiate autoimmune thyroiditis; and 2) once activated, for example by a virus, T cells could release gamma-interferon and induce thyroid cell HLA-DR and -DQ antigen expression; these Ia-positive thyroid cells could then have a role in maintaining or enhancing the autoimmune response.

Expression of HLA-DR and HLA-DQ antigens on cells within the cartilage-pannus junction in rheumatoid arthritis.

The cartilage-pannus junction in joints from patients with active rheumatoid arthritis was studied by means of immunohistochemical analysis of frozen sections, using monoclonal antibodies directed against HLA-DR, HLA-DQ class II transplantation antigens, against the transferrin receptor and against T-lymphocyte subpopulations. Expression of HLA-DR antigens was seen on a large number of synovial cells in immediate contact with the cartilage, whereas the expression of HLA-DQ antigens was only seen on a subfraction of the HLA-DR-positive cells. Most of the cells in close contact with the cartilage expressed the transferrin receptor, indicating a proliferative state of these cells. It is suggested that class II antigen-expressing synovial cells in immediate contact with the cartilage in rheumatoid joints might, in addition to their potential role in the destructive process, also serve functions in the elicitation of immune reactions against molecules released from the cartilage.