Fernanda Guedes

In situ immune responses to interstitial pneumonitis in human visceral leishmaniasis.

Lung disease during active human visceral leishmaniasis is frequently reported. As such, studies have associated pulmonary symptoms to interstitial pneumonitis with a mononuclear infiltrate. However, the immune response in this condition has never been described before. The aim of this study was to determine the immunophenotypic pattern and cytokine profile of lung involvement (IPL) in human visceral leishmaniasis. Quantitative methods of analysis were performed using immunohistochemistry, and were compared with a control group of normal lung. Interstitial macrophages and cd8 cells were increased in IPL, and IL‐4 as well as TNF‐α displayed increased expression when compared to the control group. This inflammatory process with a Th2 pattern, as suggested by increased IL‐4 and low IFN‐γ expression, is consistent with the immune response in other organs of visceral leishmaniasis. The microenvironment of the immune response in this condition is associated with lung disease in patients with interstitial pneumonitis related to visceral leishmaniasis, increasing the chance of bacterial infection.

Role of mast cells as IL10 producing cells in paracoccidioidomycosis skin lesions

Recent works have demonstrated that mast cells may have an important role in immunologic reactions and inflammation once they synthesize and secrete many cytokines including IL4, IL5, IL6 and TNF-α. We have conducted research in order to verify if mast cells would participate in the local inflammatory immune response against Paracoccidioides brasiliensis in skin lesions characterized by a Th2 pattern of cytokines. Fifty-nine skin biopsies with previous histopathological diagnosis of paracoccidioidomycosis and immunohistochemical characterization of cytokines present in the inflammatory infiltrate were classified in three groups: group 1 (G1), with compact granuloma and a Th1 pattern of cytokines; group 2 (G2), with loose granuloma and a Th2 pattern of cytokines; group 3 (G3), both kind of granuloma in the same lesion, characterized by cytokines from Th1 and Th2 patterns. Ten biopsies from normal skin were used as control group. Mast cells were visualized and quantified by a toluidine blue/HCl staining and a double immunostaining was performed to detect a co-localization of mast cells and IL10. G2 presented an increased number of mast cells when compared to G1, G3 and control group and we frequently could find mast cells expressing IL10 in G2. The data obtained suggest that mast cells participate in the immune response against P. brasiliensis in skin lesions with loose granuloma and a Th2 pattern of cytokines. Considering these results, mast cells could constitute a source of IL10, contributing to a non-effective response against fungal antigens.

Análise da herança da resistência a Puccinia psidii em progênies de híbridos interespecíficos de eucalipto avaliadas sob condições naturais de infecção

Rust caused by the fungus Puccinia psidii is currently the most important disease of eucalyptus. It is widely disseminated in Brazil, and causes serious damage in nurseries and plantation areas. The identification of resistant germplasm along with knowledge of the genetic basis of resistance heredity are the first requirements for the success of breeding programs aiming to develop resistant varieties. Earlier studies carried out under controlled conditions suggested a monogenic control as well as the participation of at least two genes promoting resistance to rust. The goal of this study was to evaluate the resistance to P. psidii under field conditions in fourteen progenies from controlled crosses and self-crosses among four hybrid clones of Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla ST Blake that contrast for resistance to the fungus. Results indicated that resistance could be explained by one locus with main effects and at least three different alleles. However, loci with minor effects may influence the resistance, since variation on severity classes was observed. Differences in segregation of resistance between reciprocal crosses were not observed, indicating absence of cytoplasmic effects.

The effects of human herpesvirus 8 infection and interferon‐γ response in cutaneous lesions of Kaposi sarcoma differ among human immunodeficiency virus‐infected and uninfected individuals

Background  Kaposi sarcoma (KS) is associated with human herpesvirus 8 (HHV‐8). The cutaneous immune response in this tumour is not well established and a better understanding is necessary.

Immunological aspects of rabies: a literature review

Rabies is a lethal disease caused by the neurotropic virus rabies virus (RABV), and it remains an important public health problem globally. It is known that the host immune response is important for control of viral infection and promoting viral clearance. In this context, it is well documented that, in addition to RABV neutralizing antibody, interferons and cell-mediated immunity also have an important role in preventing the establishment of disease. On the other hand, RABV suppresses host immunity through different mechanisms, for example, direct inhibition of host gene expression, sequestration of pathogen-associated molecular patterns, or modification of cytokine signalling pathways, which hinder the protective host immune responses to RABV infection. Here, we review the immunological aspects of rabies, highlighting innate and adaptive immunity, as well as the host evasion immune mechanisms used by the virus. Finally, we briefly discuss how this knowledge can direct new research and be harnessed for future therapeutic strategies.

Inate immunity in rosacea. Langerhans cells, plasmacytoid dentritic cells, Toll-like receptors and inducible oxide nitric synthase (iNOS) expression in skin specimens: case-control study

Rosacea is a chronic inflammatory condition with predominant facial involvement. Because of that, many patients sense that rosacea affects quality of life. The etiology of rosacea remains unknown. Recent studies have suggested that aberrant innate immunity is central to this disease. The aim of this study was to examine the presence of Langerhans cells, plasmacytoid dentritic cells (PDC), the expression of Toll-like receptors (TLR) and inducible oxide nitric synthase (iNOS) in skin of patients with rosacea, to highlight the participation of innate immunity in its pathogenesis. 28 biopsy specimens were taken from patients with clinical and histopathological findings of rosacea. Immunohistochemical demonstration of Langerhans cells (anti-CD1a antibody), PDC (anti-CD 123 antibody), TLR2, TLR4 and iNOS was performed in skin samples and compared with normal skin controls. The expression of Langerhans cells was lower in rosacea group than in control group. PDC were found in skin samples of rosacea as isolated cells and forming small clusters. Expression of TLR2, TLR4 and iNOS was higher in rosacea samples than in normal skin controls. This research demonstrates early and late stage components of innate immunity in specimens of rosacea ratifying the existence of an altered innate immunity in its pathogenesis.

Immunohistochemical evaluation of skin before and after micro-ablative fractional erbium-doped yttrium aluminum garnet laser treatment.

The authors have indicated no significant interest with commercial supporters.

Interaction of human papillomavirus DNA with factor XIIIa-positive dermal dendrocytes in vulvar lesions.

Sir, Human papillomaviruses (HPVs) are double-stranded DNA virus with over 100 different identified types. The virus mainly infects the cutaneous and mucosal squamous stratified epithelia of the anogenital region. HPV replication is linked to the differentiation and maturation of squamous cells, followed by terminal differentiation, with hyperplasia associated with the formation of local lesions (1–3). Some factors minimize or prevent the exposure of HPV to the immune system. The immune escape mechanisms are related to the absence of viral lyses in keratinocytes, or the absence of infection and replication of antigen-presenting cells (APC) in epithelium (1). Langerhans’ cells (LC) are dendritic cells that engulf and process antigen, and migrate through the dermis to draining lymph nodes (4). Factor XIIIa+ dermal dendrocytes (FXIIIa+ DD) constitute another skin dendritic cell population. They are able to differentiate and migrate to epidermis, indicating an interaction between dermis and epidermis in order to develop an immune response (5, 6). Although recent studies have shown FXIIIa+ DD involvement in other infectious process (7, 8), their interaction with HPV has been poorly explored (9). It has been demonstrated that in HPV infection of the lower genital tract, the virus has a direct effect on the local immune response, which may result in a malignant transformation. As shown previously, HPV alone decreases the number of cervical LC and induces changes in the pattern of cytokines released by these cells (10, 11). The role of LC in the immune response to HPV infection has been well studied in uterine cervix lesions. There are, however, other aspects to be clarified concerning the role of dendritic cell populations in HPV lesions. The aim of this study was to improve our knowledge of HPV infection of the vulva, focusing on the role of FXIIIa+ DD in such lesions.