3D Culturing of Organoids from the Intestinal Villi Epithelium Undergoing Dedifferentiation

Clonogenicity of organoids from the intestinal epithelium is attributed to the presence of stem cells therein. The mouse small intestinal epithelium is ...

Pennsylvania State University College of Medicine

Two school-going siblings from a family residing in a presumed malaria non-endemic locality ∼90 km from Mangalore city in southwestern India contracted Plasmodium falciparum infection. In both cases, misunderstanding of initial clinical symptoms as due to viral hepatitis resulted in progression to severe malaria before malaria treatment was initiated. Despite treatment at a tertiary hospital, the children died of cerebral malaria and multi-organ dysfunction. Active case detection in the affected locality suggested that the infection was transmitted from infected individuals who worked in nearby malaria-endemic areas and periodically visited their families. A lesson from this study is that lethal falciparum malaria can be transmitted in regions of India, believed to be non-endemic for the disease, resulting in fatal outcomes if diagnosis is missed or delayed. Implementation of effective surveillance and control measures as well as preparedness for malaria detection and diagnosis are necessary in areas that are potentially disposed to malaria transmission even though they are presumed to be non-endemic. 

Malaria Transmission Under an Unusual Circumstance Causing Death in Two Siblings.

In malaria, CD36 plays several roles, including mediating parasite sequestration to host organs, phagocytic clearance of parasites, and regulation of immunity. Although the functions of CD36 in parasite sequestration and phagocytosis have been clearly defined, less is known about its role in malaria immunity. Here, to understand the function of CD36 in malaria immunity, we studied parasite growth, innate and adaptive immune responses, and host survival in WT and  mice infected with a non-lethal strain of  Compared with  mice, WT mice had lower parasitemias and were resistant to death. At early but not at later stages of infection, WT mice had higher circulatory proinflammatory cytokines and lower anti-inflammatory cytokines than  mice. WT mice showed higher frequencies of proinflammatory cytokine-producing and lower frequencies of anti-inflammatory cytokine-producing dendritic cells (DCs) and natural killer cells than  mice. Cytokines produced by co-cultures of DCs from infected mice and ovalbumin-specific, MHC class II-restricted α/β (OT-II) T cells reflected CD36-dependent DC function. WT mice also showed increased Th1 and reduced Th2 responses compared with  mice, mainly at early stages of infection. Furthermore, in infected WT mice, macrophages and neutrophils expressed higher levels of phagocytic receptors and showed enhanced phagocytosis of parasite-infected erythrocytes than those in  mice in an IFN-γ-dependent manner. However, there were no differences in malaria-induced humoral responses between WT and  mice. Overall, the results show that CD36 plays a significant role in controlling parasite burden by contributing to proinflammatory cytokine responses by DCs and natural killer cells, Th1 development, phagocytic receptor expression, and phagocytic activity.

CD36 receptor regulates malaria-induced immune responses primarily at early blood stage infection contributing to parasitemia control and resistance to mortality.

Malaria is highly prevalent in many parts of India and the Indian subcontinent. Mangaluru, a city in the southwest coastal region of Karnataka state in India, and surrounding areas are malaria endemic with 10-12 annual parasite index. Despite high endemicity, to-date, very little has been reported on the epidemiology and burden of malaria in this area.

Malaria prevalence in Mangaluru city area in the southwestern coastal region of India.

Dakshina Kannada district in the Southwestern region of Karnataka state, India, including Mangaluru city is endemic to malaria. About 80% of malaria infections in Mangaluru and its surrounding areas are caused by  and the remainder is due to . Malaria-associated clinical complications significantly occur in this region. Here, we report the pathological conditions of 41 cases of fatal severe malaria, admitted to the district government hospital in Mangaluru city during January 2013 through December 2016. The results of clinical, hematological, and biochemical analyses showed that most of these severe malaria cases were associated with thrombocytopenia, anemia, metabolic acidosis, acute respiratory distress, and single or multi-organ dysfunction involving liver, kidney, and brain. Of the 41 fatal malaria cases, 24, 10, and seven patients had , , and  and  mixed infections, respectively. These data suggest that besides  that is known to extensively cause severe and fatal malaria illnesses,  causes fatal illnesses substantially in this region, an observation that is consistent with recent findings in other regions.

Malaria Severity in Mangaluru City in the Southwestern Coastal Region of India.

Thrombocytopenia is a most commonly observed complication during malaria infections. Inflammatory cytokines such as IL-1, IL-6, and IL-10 have been documented in malaria induced thrombocytopaenia. This study was aimed to understand the possible relationship between inflammatory cytokines across varying degrees of thrombocytopenia during ,  and mixed infections.

Association between Inflammatory Cytokine Levels and Thrombocytopenia during  and  Infections in South-Western Coastal Region of India.

Dysregulated production of inflammatory cytokines might play important role in anemia during malaria infection. The objective of this study was to assess the extent of anemia due to malaria, associated complications, and inflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin [IL]-6, and IL-10) across varying anemic intensity during malaria infections.

Association between inflammatory cytokine levels and anemia during  and  infections in Mangaluru: A Southwestern Coastal Region of India.

The aim of this study was to assess the clinical profile, severity and complications of patients suffering from malaria in Mangaluru, a southwestern coastal city in India. A total of 579 patients, who were treated at the District Wenlock Hospital, Mangaluru, and 168 healthy controls were recruited in this study. The clinical profile, haematological and biochemical parameters, and disease complications were assessed. The majority of patients were treated as outpatients and patients who had severe clinical conditions were admitted to the hospital for treatment and supportive care. Among the total 579 patients recruited in this study, the distribution of P. vivax, P. falciparum and mixed infections were 364 (62.9%), 150 (25.9%) and 65 (11.2%), respectively. Among these, 506 (87.4%) had mild malaria, whereas 73 (12.6%) had severe malaria. Overall, the clinical features and severity of malaria in P. vivax and mixed infection patients were comparable to P. falciparum patients, albeit with some significant differences. The clinical complications in severe malaria cases included thrombocytopenia (50.7%), metabolic acidosis (30.1%), severe anaemia (26.0%), jaundice (21.9%), hepatic dysfunction (15.1%), acute renal failure (6.8%), haematuria (8.2%), hypotension (9.6%), cerebral malaria (1.4%) and acute respiratory distress syndrome (1.4%). All the patients with severe malaria recruited in our study were successfully treated and discharged. Majority of patients had mild malaria, likely due to seeking treatment soon after experiencing symptoms and/or having preexisting immune protection. However, a significant number of patients had severe malaria and required hospital admission indicating that there is a substantial need for creating awareness among vulnerable immigrant population. Implementing effective surveillance and vector control measures in malaria hotspot locations in the city and educating people about preventive measures are likely to reduce the malaria burden in this endemic region.

Clinical features and haematological parameters among malaria patients in Mangaluru city area in the southwestern coastal region of India.

Merozoite surface protein-1 (MSP-1) of malaria parasites has been extensively studied as a malaria vaccine candidate and the antibody response to this protein is an important indicator of protective immunity to malaria. Mangaluru city and its surrounding areas in southwestern India are endemic to malaria with  being the most widespread and prevalent species although  also frequently infects. However, no information is available on the level of protective immunity in this population. In this regard, a prospective hospital-based study was performed in malarial patients to assess antibody responses against the 19-kDa C-terminal portion of  and  MSP-1 (MSP-1). Serum samples from 51 healthy endemic controls and 267 infected individuals were collected and anti-MSP-1 antibody levels were analyzed by ELISA. The possible association between the antibody responses and morbidity parameters such as malarial anemia and thrombocytopenia was investigated. Among the 267 infected cases, 144 had  and 123 had  infections. Significant levels of anti-MSP-1 antibody were observed both in  (123/144; 85.4%) and .  (108/123; 87.9%) infected individuals. In both type of infections, the major antibody isotypes were IgG1 and IgG3. The IgG levels were found to be increased in patients with severe anemia and thrombocytopenia. The antibody levels were also higher in infected individuals who had several previous infections, although antibodies produced during previous infections were short lived. The predominance of cytophilic anti-MSP-1 IgG1 and IgG3 antibodies suggests the possibility of a dual role of Pv MSP-1 and Pf MSP-1 during malarial immunity and pathogenesis.

Acquired antibody responses against merozoite surface protein-1 antigen during  and  infections in South Indian city of Mangaluru.

Cytokine responses to malaria play important roles in both protective immunity development and pathogenesis. Although the roles of cytokines such as TNF-α, IL-12, IFN-γ, and IL-10 in immunity and pathogenesis to the blood stage malaria are largely known, the role of IL-4 remains less understood. IL-4 targets many cell types and induces multiple effects, including cell proliferation, gene expression, protection from apoptosis, and immune regulation. Accordingly, IL-4 has been exploited as a therapeutic for several inflammatory diseases. Malaria caused by  manifests in many organ-specific fatal pathologies, including cerebral malaria (CM), driven by a high parasite load, leading to parasite sequestration in organs and consequent excessive inflammatory responses and endothelial damage. We investigated the therapeutic potential of IL-4 against fatal malaria in  ANKA-infected C57BL/6J mice, an experimental CM model. IL-4 treatment significantly reduced parasitemia, CM pathology, and mortality. The therapeutic effect of IL-4 is mediated through multiple mechanisms, including enhanced parasite clearance mediated by upregulation of phagocytic receptors and increased IgM production, and decreased brain inflammatory responses, including reduced chemokine (CXCL10) production, reduced chemokine receptor (CXCR3) and adhesion molecule (LFA-1) expression by T cells, and downregulation of cytotoxic T cell lytic potential. IL-4 treatment markedly reduced the infiltration of CD8 T cells and brain pathology. STAT6, PI3K-Akt-NF-κB, and Src signaling mediated the cellular and molecular events that contributed to the IL-4-dependent decrease in parasitemia. Overall, our results provide mechanistic insights into how IL-4 treatment mitigates experimental CM and have implications in developing treatment strategies for organ-specific fatal malaria.

Kishore Punnath

Department of Pharmacology

Pennsylvania State University College of Medicine

3D Culturing of Organoids from the Intestinal Villi Epithelium Undergoing Dedifferentiation

Kishore Punnath

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Pharmacology

Pennsylvania State University College of Medicine

3D Culturing of Organoids from the Intestinal Villi Epithelium Undergoing Dedifferentiation

Department of Pharmacology