Clinical immunology and immunopathology最新文献

In a small group of subjects we had identified persistent expansions (range 6–72%) of CD4⁺CD8⁺double-positive (DP) peripheral blood (PB) cells which express the CD8 α/α homodimer. Here, DP cells present in a larger cohort were further investigated and found by FACS analysis to express a single or a dominant TCRBV family. In these subjects, with a mean age of about 64 years, expansions of CD4⁺cells with the same TCRBV family specificity as in the respective DP cells also were consistently detected. TCR heterogeneity of the dominant TCRBV family was specifically evaluated: The amplified CDR3 region was cloned and found to consist of one single or two largely dominant sequence patterns. Furthermore, cloning of the CDR3 region from FACS-sorted DP, CD4⁺, or CD8⁺cells indicates that both DP and CD4⁺, but not CD8⁺cells, isolated from the same individual possess a striking identity of the CDR3 regions. As indicated by FACS analysis, the clonally expanded cells occur in the CD4⁺CD28⁻cells. Taken together, these results suggest that expanded CD4⁺CD28⁻cells might also acquire CD8 α/α expression and become DP and imply that CD4 clonality is a more frequent phenomenon than previously suspected. In conclusion, the persistent expansions described in this report represent a novel group of age-related benign clonal expansions of still undefined significance of a rare CD28⁻T cell subset.

Fibroblast growth factor-1 (FGF-1) is an inducer of angiogenesis, the growth of new blood vessels. The expression and localization of FGF-1 (acidic FGF) and FGF receptor (FGFR)-1 in mammary tissues from patients with breast cancer was investigated using Western blot analysis and immunohistochemistry. The affinity-purified FGF-1 antibody which did not have cross-reactivity to FGF-2 (basic FGF) was used in this study. Western blot analysis demonstrated the presence of FGF-1 protein in all of the samples from breast cancer, but not benign tumors such as mastopathy and fibroadenoma. To assess the localization of FGF-1 in cancer tissues, immunostaining with specific antibody was performed. All samples from breast cancer displayed significantly intense staining with FGF-1 antibody. The extent and intensity of immunoreactive FGF-1 polypeptides in cancer cells was statistically much greater than those of cells from fibroademoma or mastopathy. Control immunostaining with normal rabbit serum or anti-FGF-1 antibody adsorbed with the recombinant FGF-1 polypeptide was completely negative. In contrast to FGF-1, Western blot analysis demonstrated the presence of FGFR-1 protein in all of the samples from breast cancer and benign tumors. By immunohistochemical analysis, the enhanced expression of FGFR-1 was observed in breast cancer cells. Benign tumor cells or interstitial cells displayed a faint expression of FGFR-1. These results demonstrated that breast cancer cells not only generated FGF-1, but also expressed FGFR-1, and FGF-1 might play a role in the proliferation of breast cancer cells not only by paracrine but also by autocrine mechanism.

Adhesion molecules are responsible for leukocyte recruitment in injured tissues. Here, the kinetics of expression and shedding of endothelial (sE-selectin-1, sP-selectin, and sICAM-1) and neutrophil (CD11b, CD62L, and CD54) adhesion molecules was investigated by serial determinations of serum concentrations in 20 patients with elective hip arthroplasty as an exemplary condition of acute inflammation in humans. Changes were related to secretion of proinflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) as their possible inducing signals. sE-selectin-1 responded to injury with a significant increase in concentrations already after 20 min, followed by sP-selectin and sICAM-1, which increased at Hour 10 and Day 1. Expression of CD11b and CD62L acutely responded to injury (within 1 h) by a parallel increase and decrease, respectively, and normalized by Day 1. Increases in concentrations of IL-1β and TNF-α preceded the increase in adhesion molecules and significantly correlated with the response of sE-selectin-1 and sICAM-1. In conclusion, the close associations between release of IL-1β and TNF-α and sE-selectin and sICAM-1 shown in this kinetic study indicates a key role of these cytokines in upregulation of endothelial rather than neutrophil adhesion molecules in vivo.

The present treatment, prophylaxis, and prognostic staging of human immunodeficiency virus (HIV) disease rely heavily on peripheral CD4⁺T lymphocyte (CD4) changes. We correlated the clinical course of events and CD4 changes among consecutive HIV-infected ethnic Chinese adults in Hong Kong. Using death as end point, the estimated proportion survival and death incidences were used to compare CDC and proposed staging criteria based on stratified baseline CD4. A separate set of baseline CD4 per microliter (/μl) (percentage lymphocytes) stratification criteria of 1, >220/μl (>12%); 2, 100–220/μl (6–12%); and 3, <100/μl, (<6%) is proposed which can be used for staging HIV-infected Chinese adults. For our study population, our proposed criteria for stratifying baseline CD4 gave better discrimination and more predictive power than the CDC criteria. We assessed the potential impact of these new proposed criteria on anti-retroviral treatment and prophylaxis against opportunistic infections in our adult HIV-infected population.

CD44 variant isoforms are frequently expressed on tissue-infiltrating lymphocytes. By the high incidence of autoimmune reactions of the skin and aiming at new strategies of therapeutic intervention, we became interested in evaluating the CD44 isoform expression profile in autoimmune reactions of the skin. Expression of CD44s, CD44v3, v5, v6, v7, v7–v8, and v10 was evaluated in 55 biopsies of lupus erythematosus, bullous pemphigoid, vasculitis, morphea, and pemphigus vulgaris. Biopsies did not contain CD44v5-, CD44v6-, CD44v7-, or CD44v7–v8-positive leukocytes. Staining with anti-CD44v10 was seen in vasculitis and occasionally in lupus erythematosus, morphea, and bullous pemphigoid. All biopsies contained CD44v3⁺leukocytes, the percentage of CD44v3⁺leukocytes being increased in autoimmune infiltrates with the exception of pemphigus vulgaris. CD44v3 was expressed by CD4⁺cells as well as by part of CD8⁺cells, Langerhans cells, and monocytes. Vascular endothelium also contained CD44v3⁺cells. Only monocytes expressed CD44v10. We assume that CD44v3 and CD44v10 may be targeting leukocytes toward the skin or allow for their retention and expansion via binding of cytokines and chemokines harbored by activated, skin-associated endothelium or provided by cells surrounding the infiltrate. The absence of CD44v6, frequently associated with lymphocyte activation, appears to be a peculiarity of skin-infiltrating leukocytes.

Patients with congenital toxoplasmosis occasionally show rises in serum antibodies toToxoplasma gondii(serological rebound), but the underlying cause remains unclear. The acute or chronic presence of available antigen often causes the appearance, in the peripheral blood, of cells actively secreting specific antibody. We have evaluated the capacity of circulating blood cells from 91 children born toT. gondii-infected mothers to actively synthesize anti-T. gondiiantibodies according to their serological status. Supernatants from 7-day cultures of peripheral blood mononuclear cells were evaluated for antibody by cytofluorimetry. Only 1 of 49 subjects with low and stable serum antibody titers produced specific antibodies on cultures, while 9 of 22 subjects with recent rebound were positive. One of the positive children alone showed clinical signs of parasite activity. These observations suggest that rebound may be associated with production of available parasite antigens, possibly associated with reactivation. Differentiation from other causes, such as polyclonal B cell stimulation, would improve our ability to detect clinically significant reactivation and to prevent complications.

Fractionation ofBorrelia burgdorferiwas made by extraction of infectious spirochetes using the detergent Triton X-114. Gel electrophoresis analysis of hydrophilic and hydrophobic proteins demonstrated that detergent extraction resulted in two populations of proteins with nonoverlapping electrophoretic profiles. Immunoblot analysis with monoclonal antibodies reactive with two abundant membrane proteins demonstrated that hydrophilic proteins were uncontaminated with hydrophobic proteins. In addition, assay of thymidine incorporation into and secretion of tumor necrosis factor-α from splenocytes coculturedin vitrowith either detergent or aqueous phase proteins showed that lymphocyte mitogenic and macrophage activation activities ofB. burgdorferiwere completely absent from the hydrophilic phase proteins. The Triton X-114 aqueous and detergent phase proteins were used to immunize BALB/c and separately μMT/μMT (B cell knockout) mice that were subsequently challenged with infectiousB. burgdorferi.The hydrophilic phase proteins were able to induce protective resistance to infection in either strain of mice demonstrating that potential candidate vaccine antigens are contained in the biochemical class of antigens which is devoid of both lymphocyte mitogen activity and major outer surface proteins. Furthermore, the ability to vaccinate B cell knockout mice suggests that the humoral antispirochete immune response is not the exclusive basis for protective immunity.

A mucosal immune response to food antigens could result in detrimental hypersensitivity responses. Therefore, the response to many orally administered antigens is downregulated by mechanisms which are not completely understood. Intestinal epithelial cells (IEC) in these tissues may play a role in these regulatory mechanisms via their secreted cytokines. Experiments with human lymphocytes or isolated CD4⁺T cells cultured with 4-day culture supernatants from human colonic carcinoma cell lines revealed that the IEC cell lines normally secreted levels of IL-7 which could enhance IL-4, but not IL-2 or IFN-γ, secretion by stimulated mixtures of lymphocyes, but not purified CD4⁺T cells. However, acid treatment of the IEC culture supernatants to activate latent TGF-β resulted in a suppression IL-4, but not IL-2 or IFN-γ, secretion. These results indicate that under normal conditions, IEC secrete latent TGF-β and IL-7, the latter of which may enhance local IL-4 secretion. However, activation of the IEC-derived TGF-β may suppress local IL-4 secretion to suppress the induction of local Th2-type responses to intestinal lumenal antigens.