Mercedes Lopez-Santalla

Increased levels of bovine serum albumin antibodies in patients with type 1 diabetes and celiac disease-related antibodies.

Objectives To detect the presence of antibodies against bovine serum albumin in a cohort of Spanish patients with type 1 insulin-dependent diabetes. Methods Antibodies were measured using an in-house enzyme-linked immunosorbent assay test in 80 patients with type 1 diabetes, subdivided according to the presence or absence in their serum of celiac disease-related antibodies. For comparison, 30 patients with celiac disease (nondiabetic), 13 patients with autoimmune thyroiditis, and 45 healthy volunteers were used. Results Thirty-one percent of patients with diabetes yielded a positive result, with a mean value of 26.1 ± 21.8 arbitrary units (AU). If the group was split into those with celiac disease-related antibodies and those lacking them, the percentages were 53% and 25%, respectively, with a mean value of 39.6 ± 28.4 AU and 22.4 ± 18.3 AU (P = 0.003), respectively. Seventy-three percent of celiac patients showed bovine serum albumin antibodies with a mean level of 38.8 ± 27.7 AU, comparable to that of patients with diabetes with celiac antibodies, but higher than the group lacking them (P = 0.001). Although 46% of patients with autoimmune thyroiditis had positive results, the level detected (22.1 ± 8.7 AU) was significantly lower than that recorded in patients with type 1 diabetes who had celiac disease antibodies (P = 0.04) and celiac patients (P = 0.04). Healthy volunteers showed no antibodies against bovine serum albumin. Conclusions These data suggest that bovine serum albumin antibodies appears in patients with a compromised epithelial permeability, and they reflect a general defect in the process of immunologic tolerance associated with a predisposition to autoimmunity, rather than immunity specific to &bgr; cells.

Higher proliferative capacity of T lymphocytes from patients with Crohn disease than from ulcerative colitis is disclosed by use of Herpesvirus saimiri-transformed T-cell lines

Background: T lymphocytes play a crucial role in the pathogenesis of inflammatory bowel disease. Achieving stable T-cell lines, rather than continuous bleeding of patients, is desirable in order to dissect their implication in the disease. Methods: Long-lasting T-cell lines from patients with Crohn disease and ulcerative colitis and from healthy volunteers have been obtained by transformation of T lymphocytes using the lymphotropic Herpesvirus saimiri. Lines were subjected to phenotypic and functional analyses, and the results compared with freshly isolated peripheral blood mononuclear cells. Results: Fresh cells revealed only minor differences between patients and controls, with regard to phenotype and proliferative capacity. In contrast, the use of T-cell lines showed that cells from Crohn disease patients, but not ulcerative colitis patients, over-responded to several membrane or cytoplasmic stimuli when compared to control T-cell lines. Thus, higher responses were found when stimulated with αCD3 and IL2, αCD3 and αCD28, IL2 alone, phorbol esters (PMA) and αCD3 and, finally, PMA and αCD2 (P < 0.05 in all instances). Further, lines from patients with Crohn disease responded more vigorously to αCD3 and αCD28 or αCD3 and PMA when compared to ulcerative colitis (P < 0.05 in both instances). Conclusions: The data obtained with these lines suggest that T cells from patients with Crohn disease differ in vivo in their proliferative capacity, as compared with those from ulcerative colitis patients, a finding that may reflect the clear Th-1 phenotype found in the former and absent in the latter.

Herpesvirus saimiri (HVS)-transformed T-cell lines: A method to study mucosal T cells in inflammatory bowel disease

Alterations in the mechanisms regulating the immune response are key elements in inflammatory bowel disease (IBD, comprising Crohn’s disease (CD) and ulcerative colitis (UC)). Although the precise aetiology remains unknown, T lymphocytes play a crucial role in its pathogenesis. Initially, descriptions of the immunological features in IBD focused on peripheral blood lymphocytes. Since these data do not necessarily reflect the situation at the mucosal milieu, it is important to assess the phenotypic profile and activation state of immune cells at this level. We have used a common lymphotropic virus of squirrel monkeys, Herpesvirus saimiri (HVS), to immortalize T cells of intestinal mucosal origin from patients and healthy individuals as controls. HVS-transformed T lymphocytes become antigenand mitogen-independent for their continuous growth and upon stimulation with membrane or transmembrane stimuli, these cells show normal downstream functional responses [1,2].

Herpesvirus saimiri transformation may help disclose inherent functional defects of mucosal T lymphocytes in patients with gastric adenocarcinoma

To dissect the phenotypic and functional features of mucosal T lymphocytes in patients with gastric adenocarcinoma, we have used the Herpesvirus saimiri transformation procedure to achieve T‐cell lines from gastric origin. Once achieved, cell function was assessed by in vitro stimulation with mitogens. CD2‐specific monoclonal antibodies (α‐CD2), alone or in combination with interleukin (IL)‐2, rendered fewer counts in patients (34 408±3965 and 52 157±6473 c.p.m., respectively) than in controls (67 471±11 755 c.p.m., P<0.01 and 77 864±12 545 c.p.m., P<0.05, respectively). Likewise, CD3‐based responses were defective in cancer cell lines: α‐CD3 (54 794±9269 vs 86 104±10 341 c.p.m., P<0.01), α‐CD3+IL‐2 (57 789±8590 vs 88855±8516 c.p.m., P<0.01) and α‐CD3+α‐CD2 (52 130±7559 vs 120 852±16 552 c.p.m., P<0.01). Finally, IL‐2 failed to adequately stimulate patient cell lines (39 310±4023 vs 60 945±9463 c.p.m., P<0.05). These results suggest that mucosal T lymphocytes in cancer patients are inherently impaired in their proliferative ability. This may be crucial in the control of tumour growth.