Biomedical subjects

V Janardhana

Publications and source records attributed to V Janardhana.

9 recordsLinked to original sources

PubMed1999

The ovine cytotoxic T lymphocyte responses to bluetongue virus.

This study uses recombinant vaccinia viruses expressing truncated or entire bluetongue virus (BTV) proteins to map the location of epitopes recognized by cytotoxic T lymphocytes (CTL) from Australian merino sheep. The non-structural protein, NS1, was recognised by CTL from all sheep, while VP2, VP3, VP5 and VP7 were recognised by CTL from only some sheep. The remaining proteins (except for VP1, which was not tested) did not contain CTL epitopes. When truncated genes were used to map the location of CTL epitopes, it was found that sheep often have CTL that recognise more than one epitope in NS1 or VP2. Overall there was considerable diversity in the CTL recognition patterns in the sheep tested.

Animals↗

PubMed1995

Antigen specificity of the ovine cytotoxic T lymphocyte response to bluetongue virus.

Bluetongue virus (BTV), an arbovirus transmitted by midges, can cause serious disease in sheep. Both virus neutralizing antibody and cytotoxic T lymphocytes (CTL) have been shown to have a role in protective immunity. In this study, the antigen specificity of CTL from BTV-immune sheep has been determined using recombinant vaccinia viruses expressing individual BTV antigens. The results show that, in the sheep studied thus far, the serotype-specific outer coat protein, VP2, and the non-structural protein, NS1 are major immunogens for CTL, with VP5 (an outer coat protein) and NS3 being minor immunogens. No VP7 (a major group-reactive inner coat protein) specific CTL were detected. The CTL from sheep immunized with serotype 1 were cross-reactive and able to recognize target cells infected with other BTV serotypes. Further work demonstrated that the cross-reactive CTL recognized NS1, but not VP2.

Animals↗

PubMed1994

Recombinant vaccinia viruses expressing interleukin-5 stimulate an earlier appearance of antibody-secreting cells in the lung.

Interleukin-5 (IL-5) is a cytokine that participates in the regulation of antibody secretion, in particular promoting the secretion of IgA at mucosal sites. In this report, recombinant vaccinia viruses expressing IL-5 have been inoculated into mice and the appearance of antibody-secreting cells in the spleen and lungs investigated. Although vaccinia virus-expressed IL-5 did not increase the level of IgA in serum, antibody-secreting cells, measured in an enzyme-linked immunosorbent spot assay, appeared earlier in lungs when the immunizing virus expressed IL-5. These early B cells secreted either IgM or IgG1.

Animals↗

PubMed1993

Protective immunity to rotavirus-induced diarrhoea is passively transferred to newborn mice from naive dams vaccinated with a single dose of a recombinant adenovirus expressing rotavirus VP7sc.

VP7sc is a novel rotavirus antigen engineered for presentation at the cell surface. Several recombinant viruses were constructed in which VP7sc was inserted into the E3 region of the human type 5 adenovirus (Ad5) genome and expression and transport of the antigen was monitored in cultured 293 cells. The recombinant virus showing the greatest level of expression (Ad5/7.4) was then used to determine whether antibodies to VP7sc could be induced in a nonhuman host. BALB/c and CBA/H mice were inoculated with Ad5/7.4 by iv, ip, oral and intranasal routes and serum antibody levels were assayed by ELISA. All vaccinated animals seroconverted but, depending on the route of vaccination, not all animals showed a significant secondary response following re-inoculation. The ability of Ad5/7.4 to induce protective immunity in mice was also examined using several vaccination regimes. A single dose of Ad5/7.4 given intranasally to dams not previously exposed to rotavirus was sufficient to induce immunity which could be passively transferred to protect suckling neonates. Recombinant adenoviruses expressing protective antigens therefore may provide an alternative to the use of attenuated rotaviruses in the development of a vaccine against gastroenteritis.

Adenoviruses, Human↗

PubMed1991

ABO blood groups in hematologic malignancies.

This article examines the genetic predisposition of individuals to lymphoma and leukemia with regard to the ABO blood groups. Blood samples from 558 patients suffering from various forms of lymphoma and leukemia were collected and typed for ABO blood groups. The ABO blood group phenotype frequencies of lymphoma patients were similar to those in control samples. Among leukemia patients, a significant increase in the frequency of the A2 phenotype was found in chronic lymphocytic leukemia. Possible mechanisms underlying the predisposition of individuals with the A2 blood group to chronic lymphocytic leukemia suggested by these preliminary results are discussed.

ABO Blood-Group System↗

PubMed1988

Immunoglobulin allotypes Gm and Km in hematologic malignancies.

Immunoglobulin allotypes of the Gm and Km systems have been compared in patients with various forms of hematologic malignancies and healthy controls of the same ethnographic background. These comparisons found an increased frequency of the haplotype Gm and a decreased frequency of Gm in patients with Hodgkin's disease; a decreased frequency of Gm in diffuse, large-cell lymphoma patients; a decreased frequency of Gm and an increased frequency of Gm in acute myeloid leukemia patients; a decreased frequency of Gm in chronic myeloid leukemia patients, and an increased frequency of the phenotype Km(1+) in chronic lymphocytic leukemia patients. These results support previous suggestions of the involvement of immunoglobulin allotypes in the susceptibility to some forms of human hematologic malignancy.

Gene Frequency↗

PubMed1988

Associations between the two serum proteins haptoglobin and transferrin and leukaemia.

Haptoglobin and transferrin (TF) types were determined for 134 patients with leukaemia of the four most common types: acute lymphocytic (ALL), chronic lymphocytic (CLL), acute myelocytic (AML) and chronic myelocytic leukaemia (CML). The phenotype HP1 was found to have an increased incidence in the total patient group due to an increased incidence in those with AML, ALL and CML compared with controls, but not in those with CLL. Although tests of association applied to each of the samples of the four common types of leukaemia produced no significant chi 2 values, they did indicate that the relative incidence (RI) was just under 2 for the groupings of the acute forms ALL and AML, the myelocytic forms AML and CML and for the combination of ALL, AML and CML, respectively. All these associations were statistically significant (p less than 0.05). Analysis of TF subtypes and leukaemia indicated a significantly increased frequency of TF C1C1 among leukaemia patients compared with controls (p less than 0.005). Analysis of the samples of each of the four common types suggested that while the RI was raised in all but ALL patients, the association was significant only in AML patients (p less than 0.05). However, when the two myelocytic types were combined the RI was 2.3 and the association was highly significant (p less than 0.005). No such association could be detected in the lymphocytic forms.

Alleles↗

PubMed1987

Occurrence of the immunoglobulin haplotypes Gm1,17;23;21 and Gm1,2,17;23;21 in a sample of Australian Caucasians.

Phenotypes positive for G2m(23) but negative for G1m(3) and G3m(5,10,11,13,14) are generally very infrequent in Caucasian populations. We recently Gm typed 372 Australian blood donors, predominantly of European descent, and found two Gm(1;23) and five Gm(1,2;23) individuals among them. This finding suggests that the haplotypes Gm1,17;23;21 and Gm1,2,17;23;21 may occur, in some European populations, with a frequency considerably higher than has been generally assumed.

Australia↗

PubMedDate not supplied

Alpha-1-antitrypsin phenotypes in leukaemia and lymphoma.

Serum samples from 564 Caucasian patients suffering from either leukaemia or lymphoma were typed for the protease inhibitor (Pi) alpha-1-antitrypsin (AAT). No evidence was found for the predisposition of any Pi phenotype to leukaemia or lymphoma. However, the frequency of PiM3 was significantly lowered among patients with acute myeloid leukaemia.

Humans↗