Naive tumor-specific CD4(+) T cells differentiated in vivo eradicate established melanoma

In vitro differentiated CD8⁺ T cells have been the primary focus of immunotherapy of cancer with little focus on CD4⁺ T cells. Immunotherapy involving in vitro differentiated T cells given after lymphodepleting regimens significantly augments antitumor immunity in animals and human patients with cancer. However, the mechanisms by which lymphopenia augments adoptive cell therapy and the means of properly differentiating T cells in vitro are still emerging. We demonstrate that naive tumor/self-specific CD4⁺ T cells naturally differentiated into T helper type 1 cytotoxic T cells in vivo and caused the regression of established tumors and depigmentation in lymphopenic hosts. Therapy was independent of vaccination, exogenous cytokine support, CD8⁺, B, natural killer (NK), and NKT cells. Proper activation of CD4⁺ T cells in vivo was important for tumor clearance, as naive tumor-specific CD4⁺ T cells could not completely treat tumor in lymphopenic common gamma chain (γ_c)–deficient hosts. γ_c signaling in the tumor-bearing host was important for survival and proper differentiation of adoptively transferred tumor-specific CD4⁺ T cells. Thus, these data provide a platform for designing immunotherapies that incorporate tumor/self-reactive CD4⁺ T cells.

Interleukin-2-dependent mechanisms of tolerance and immunity in vivo

IL-2 is a critical T cell growth factor in vitro, but predominantly mediates tolerance in vivo. IL-2 is mainly produced by CD4(+) Th cells, but the role of Th cell-derived IL-2 in vivo is controversial. We demonstrate that during immunity to a tumor/self-Ag, the predominant role of Th cell-derived IL-2 was to maintain IL-2Ralpha (CD25) on CD4(+) T regulatory cells (T(reg)), which resulted in their maintenance of the T(reg) cell lineage factor, Forkhead/winged helix transcription factor (Foxp3), and tolerance. However, in the absence of T(reg) cells, Th cell-derived IL-2 maintained effector T cells and caused autoimmunity. IL-2R signaling was indispensable for T(reg) cell homeostasis and efficient suppressor function in vivo, but, surprisingly, was not required for their generation, because IL-2(-/-) and CD25(-/-) mice both contained Foxp3(+) T cells in the periphery. IL-2R signaling was also important for CD8(+) T cell immunity, because CD25(-/-) tumor-reactive CD8(+) T cells failed to affect established tumors. Conversely, IL-2R signaling was not required for Th cell function. Lastly, administration of anti-IL-2 plus exogenous IL-15 to tumor-bearing mice enhanced the adoptive immunotherapy of cancer. Therefore, Th cell-derived IL-2 paradoxically controls both tolerance and immunity to a tumor/self-Ag in vivo.

Epidemiologic characteristics of rhinitis in Turkish children: the International Study of Asthma and Allergies in Childhood (ISAAC) phase 2

Rhinitis is a common problem with important comorbidities. In order to search the association between rhinitis, allergic phenotypes and other risk factors in Turkish children, a parental questionnaire about allergic diseases and risk factors, and skin prick test (SPT) with 13 inhalant allergens were performed in a population-based sample of 2774 children aged 9-11 yr. Bronchoprovocation testing with hypertonic saline (HS)and total IgE analysis were limited to a subsample of 350 children. Rhinitis was defined as a problem with sneezing, rhinorrhea, or nasal congestion when the child did not have a viral respiratory infection. The prevalences of ever rhinitis, current (last 12 months) rhinitis (CR), and ever hay fever were 36.3%, 30.6%, and 8.3%, respectively. SPT positivity rate was 20.4% among children with CR. Current wheezing and flexural dermatitis were significantly associated with CR. CR significantly increased the risk of asthma among both atopic and non-atopic subjects [odds ratio (OR), 3.98; 95% CI, 1.81-8.76; and OR, 2.79; 95% CI, 1.82-4.26, respectively]. The association between CR and bronchial hyperreactivity (BHR) was not significant. The multiple logistic regression analysis revealed family atopy (OR=2.25, 95% CI=1.79-2.83, p<0.001), current indoor heating with gas stove (OR=1.78, 95% CI=1.18-2.64, p=0.006) and dampness/molds at home during the first year of life (OR=1.70, 95% CI=1.25-2.31, p=0.001) as significant risk factors for CR. Turkish school children showed a high prevalence of rhinitis with a preponderance of non-atopics. The highly significant association between rhinitis and asthma independent of atopic sensitization emphasize the importance of non-atopic forms of rhinitis.

CD8+ T cell immunity against a tumor/self-antigen is augmented by CD4+ T helper cells and hindered by naturally occurring T regulatory cells

CD4(+) T cells control the effector function, memory, and maintenance of CD8(+) T cells. Paradoxically, we found that absence of CD4(+) T cells enhanced adoptive immunotherapy of cancer when using CD8(+) T cells directed against a persisting tumor/self-Ag. However, adoptive transfer of CD4(+)CD25(-) Th cells (Th cells) with tumor/self-reactive CD8(+) T cells and vaccination into CD4(+) T cell-deficient hosts induced autoimmunity and regression of established melanoma. Transfer of CD4(+) T cells that contained a mixture of Th and CD4(+)CD25(+) T regulatory cells (T(reg) cells) or T(reg) cells alone prevented effective adoptive immunotherapy. Maintenance of CD8(+) T cell numbers and function was dependent on Th cells that were capable of IL-2 production because therapy failed when Th cells were derived from IL-2(-/-) mice. These findings reveal that Th cells can help break tolerance to a persisting self-Ag and treat established tumors through an IL-2-dependent mechanism, but requires simultaneous absence of naturally occurring T(reg) cells to be effective.

Vocal cord dysfunction: more morbid than asthma if misdiagnosed

Vocal cord dysfunction may lead to respiratory distress, which in turn may cause the misdiagnosis of asthma. We present two adolescents who were misdiagnosed as asthmatic and aggressively treated for asthma with resulting iatrogenic complications. Vocal cord dysfunction simulating or coexisting with asthma should be considered especially in patients with frequent emergency visits for episodic dyspnea despite aggressive treatment.

Effect of formoterol on clinical parameters and lung functions in patients with bronchial asthma: a randomised controlled trial

AIMS

To determine the role of formoterol in the treatment of children with bronchial asthma who are symptomatic despite regular use of inhaled corticosteroids.

METHODS

A randomised, double blind, parallel group, placebo controlled study to investigate the effects of inhaled formoterol (12 microg twice a day) in 32 children with moderate to severe bronchial asthma. The study consisted of two week run in periods and six week treatment periods, during both of which the patients continued their regular anti-inflammatory drugs. The efficacy parameters were symptom scores, bronchodilator use, daily peak expiratory flow rates (PEFR), methacholine hyper-reactivity, forced expiratory volume in one second (FEV1), lung volumes, and airway conductance.

RESULTS

Formoterol treatment for six weeks decreased symptom scores, PEFR variability, and the number of rescue salbutamol doses, and increased morning and evening PEFR significantly. No adverse reactions were seen.

CONCLUSION

These findings suggest that inhaled formoterol is effective in controlling chronic asthma symptoms in children who are symptomatic despite regular use of inhaled corticosteroids.