Review of Dendritic Cells, Their Role in Clinical Immunology, and Distribution in Various Animal Species.

Dendritic cells (DCs) are cells derived from the hematopoietic stem cells (HSCs) of the bone marrow and form a widely distributed cellular system throughout the body. They are the most efficient, potent, and professional antigen-presenting cells (APCs) of the immune system, inducing and dispersing a primary immune response by the activation of naïve T-cells, and playing an important role in the induction and maintenance of immune tolerance under homeostatic conditions. Thus, this review has elucidated the general aspects of DCs as well as the current dynamic perspectives and distribution of DCs in humans and in various species of animals that includes mouse, rat, birds, dog, cat, horse, cattle, sheep, pig, and non-human primates. Besides the role that DCs play in immune response, they also play a pathogenic role in many diseases, thus becoming a target in disease prevention and treatment. In addition, its roles in clinical immunology have also been addressed, which include its involvement in transplantation, autoimmune disease, viral infections, cancer, and as a vaccine target. Therefore, based on the current knowledge and understanding of the important roles they play, DCs can be used in the future as a powerful tool for manipulating the immune system.

Molecular detection of feline leukemia virus in clinically ill cats in Klang Valley, Malaysia.

BACKGROUND AND AIM: Feline leukemia virus (FeLV) is classified as Retroviridae gammaretrovirus. FeLV occurs worldwide, including Malaysia. Thus far, only one decade-old study on molecular characterization of Malaysian FeLV isolates exists, which resulted in a scarcity of updated information of current FeLV isolates circulating in Malaysia. This study was conducted to determine the status of FeLV in clinically ill cats and to study the molecular characterization and phylogenetic relatedness of the current isolates. MATERIALS AND METHODS: Convenience sampling was performed in 20 cats from the Gasing Veterinary Hospital in Selangor. Plasma and saliva samples were collected from 15 clinically ill cats and 5 healthy cats subjected to one-step reverse transcription-polymerase chain reaction with primers targeting a highly conserved gene of U3-LTR-gag. RESULTS: Two clinically ill cats' plasma and saliva samples tested positive for FeLV RNA. Partial nucleotide sequencing and phylogenetic analysis revealed that the current isolates were 94-99% homologous to the previous Malaysian and Japanese FeLV isolates. CONCLUSION: Current FeLV isolates from this study displayed higher similarity with the previous Malaysian isolates, signifying that a similar FeLV strain circulated among the cat population in Selangor.

Histopathological changes of acetaminophen-induced liver injury and subsequent liver regeneration in BALB/C and ICR mice.

BACKGROUND AND AIM: Laboratory mice are widely used as a research model to provide insights into toxicological studies of various xenobiotic. Acetaminophen (APAP) is an antipyretic and analgesic drug that is commonly known as paracetamol, an ideal hepatotoxicant to exhibit centrilobular necrosis in laboratory mice to resemble humans. However, assessment of histopathological changes between mouse strains is important to decide the optimal mouse model used in APAP toxicity study. Therefore, we aim to assess the histomorphological features of APAP-induced liver injury (AILI) in BALB/C and Institute of Cancer Research (ICR) mice. MATERIALS AND METHODS: Twenty-five ICR mice and 20 BALB/C mice were used where five animals as control and the rest were randomly divided into four time points at 5, 10, 24 and 48 hours post-dosing (hpd). They were induced with 500 mg/kg APAP intraperitoneally. Liver sections were processed for hematoxylin-eosin staining and histopathological changes were scored based on grading methods. RESULTS: Intense centrilobular damage was observed as early as 5 hpd in BALB/C as compared to ICR mice, which was observed at 10 hpd. The difference of liver injury between ICR and BALB/C mice is due to dissimilarity in the genetic line-up that related to different elimination pathways of APAP toxicity. However, at 24 hpd, the damage was markedly subsided and liver regeneration had taken place for both ICR and BALB/C groups with evidence of mitotic figures. This study showed that normal liver architecture was restored after the clearance of toxic insult. CONCLUSION: AILI was exhibited earlier in BALB/C than ICR mice but both underwent liver recovery at later time points.